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Water Supply Demand Strategy

7 December 2011

Water Supply Demand Strategy

7 December 2011

This document was prepared with the assistance of: Sinclair Knight Merz ABN 37 001 024 095 Level 11, 452 Flinders Street, Melbourne VIC 3000 PO Box 312, Flinders Lane, Melbourne VIC 8009 Tel: +61 3 8668 3100 Fax: +61 3 8668 3400 Web: www.skmconsulting.com The SKM logo trade mark is a registered trade mark of Sinclair Knight Merz Pty Ltd.

LIMITATION: This report has been prepared on behalf of and for the exclusive use of Sinclair Knight Merz Pty Ltd’s Client, and is subject to and issued in connection with the provisions of the agreement between Sinclair Knight Merz and its Client. Sinclair Knight Merz accepts no liability or responsibility whatsoever for or in respect of any use of or reliance upon this report by any third party.

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Executive Summary

South Gippsland Water has responsibility for the current operation and future system planning for

10 separate town water supply systems in its district shown in Figure 1. Future system planning

has involved developing, for the district, a Water Supply Demand Strategy (WSDS). Key to this

WSDS, which updates South Gippsland Water‟s previous WSDS prepared in 2007, is the

possibility of connecting South Gippsland Water‟s supply systems to the Melbourne supply system.

Connection to the Melbourne supply system provides South Gippsland Water with an opportunity

to access a significant volume of water that is not dependent on rainfall. This has the potential to

reduce South Gippsland Water‟s supply risk due to climate change. The approach to this planning

study has therefore been to consider future supply options both with and without a connection to

the Melbourne supply system.

Figure 1 Locality Map

South Gippsland continues to grow – with a high rate of growth particularly evident along the

coastal strip near Inverloch. Demands for water are expected to increase because towns supplied

PAGE ii

by South Gippsland Water are close to the ever expanding Melbourne fringe. There is also

potential for major industry to relocate to the area. Some industrial water customers who produce

saline wastewater are expected to move from Melbourne to take advantage of South Gippsland

Water‟s saline outfall transfer system, which the Victorian Environment Protection Authority

(EPA) has noted as being an asset of State-wide significance. Some of South Gippsland Water‟s

existing industrial water customers also have the potential to expand, particularly in the food

processing industry. The dairy industry – producing milk, cheese, butter, yoghurt and now more

sophisticated protein and pharmaceutical products – is one of the main industries in the region.

South Gippsland Water supplies a limited amount of water to dairy farms and a considerable

amount of water to dairy processing factories in Leongatha and Korumburra. These factories

require a very reliable supply of water.

Water supply and demand strategies for each supply system have been developed for two demand

scenarios with sensitivities for additional demand from connection of unserviced coastal towns.

The two scenarios are for growth based on Victoria in Future (ViF) forecasts available from the

State Government, and a Local Growth forecast based on South Gippsland Water‟s assumed higher

growth scenario, including allowances for higher demand from existing and future major industries.

Figure 2 indicates that total water demand from South Gippsland Water‟s supply systems is

expected to increase by at least one third over the next 50 years and could potentially double over

this time.

Figure 2 Anticipated Growth in Demand for Urban Water in South Gippsland

0

2000

4000

6000

8000

10000

12000

14000

2009 2014 2019 2024 2029 2034 2039 2044 2049 2054 2059

Vo

lum

e (M

L/y

r)

Victoria in Future Growth Scenario (including medium climate change, additional demand reduction measures)

Higher Growth Scenario (including medium climate change, no additional demand reduction measures, connection to unserviced towns near Inverloch and south of Fish Creek)

Anticipated uncertainty in future demand for water

PAGE iii

South Gippsland Water foresaw the risk of shortfalls in some of its water supply systems many

years ago and commissioned strategic assessments of demand and future supply alternatives. This

update to the Water Supply Demand Strategy in 2011 follows on from the previous update in 2007.

Since that time, South Gippsland Water has implemented its strategy to secure additional water

supplies for Leongatha, Korumburra and Yarram with the approval of government environment

agencies. The 2011 strategy now also takes into account the effects of the 2006/07 drought year,

changes in South Gippsland Water‟s infrastructure and operation as a result of the drought, the

2006 population census results and projections, and the potential to obtain a supply from the

Melbourne Water Supply System. Melbourne‟s circumstances with supply and demand for water

some years ago led the State Government to contract for the design, build and operation of a

desalination plant at Wonthaggi with connecting pipeline to the Melbourne water supply system.

When operable after 2011, water will be available from this connecting pipeline to the Lance creek

water supply system.

In 2010 the State Government funded a 10 ML/d pipeline to provide a water supply from the Lance

Creek water supply system (adjacent to the Powlett River near Wonthaggi) to the desalination

construction site. After construction of the desalination plant, which is to be commissioned in

2011, this pipeline will be available to South Gippsland Water to connect the Lance Creek system

to the Melbourne supply system. The Lance Creek system is currently a very reliable source of

water for the towns of Wonthaggi, Cape Paterson and Inverloch. The availability of a connection

to the Melbourne supply system provides increased drought security to these towns, as well as the

potential to connect other less reliable supply systems and currently unserviced towns.

The approach to this planning study has been to consider future supply options for the northern,

southern and central towns both with and without a connection to the Melbourne supply system.

South Gippsland Water must carefully consider any cost implications associated with being

connected to the Melbourne supply system, and is currently preparing business cases to assess this

issue. The connection to the Melbourne supply system also has implications for South Gippsland

Water‟s water treatment operations. The preferred strategy for the northern, southern and central

towns, and the unserviced coastal towns, will not be known until the business cases are completed.

Therefore South Gippsland Water has developed a dual strategy which allows for the possibility of

either developing local water sources or utilising water from the Melbourne supply system.

For the WSDS, South Gippsland Water has planned its demand reduction and supply enhancement

measures on the assumption of medium climate change conditions over the next 50 years, based on

CSIRO‟s climate change projections, as reported in Jones and Durack (2005). South Gippsland

Water has also prepared itself for the possibility that the low inflow conditions observed since the

late 1990s could continue indefinitely. The “ongoing low flows” scenario assumes that long-term

climate and streamflow conditions will be similar to those experienced from 1997 to 2009. Many

of South Gippsland Water‟s supply systems have only small storage capacities relative to demand

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and inflows, so South Gippsland Water has also considered the resilience of each supply system to

severe prolonged drought based on a repeat of the 2006/07 drought in consecutive years.

Strategy Outcomes

The key outcomes from the WSDS assessment process were:

South Gippsland Water‟s customers have responded well to calls to reduce water consumption.

Consumption has reduced significantly over the last few years and these reductions have been

sustained. In many cases this has been achieved despite increases in population and the

number of dwellings. South Gippsland Water‟s demand reduction measures targeting specific

user groups have also been successful, such as the measures introduced to assist rural

customers with alternative water supplies at Fish Creek and the WaterMAP program for

industrial customers. Water conservation remains a top priority – water must be used more

efficiently.

Further demand reduction will be pursued in all supply systems with a target set for:

– 25% reduction in per capita demand by the year 2015 relative to 1990s average demand;

– 30% reduction in per capita demand by the year 2020 relative to 1990s average demand.

These demand reductions will be insufficient to maintain supply at South Gippsland Water‟s

level of service objective for reliability of supply in some supply systems over the 50 year

planning horizon. Supply augmentation will be required in these systems.

For South Gippsland Water’s northern and southern towns, which includes Poowong,

Loch, Nyora, Korumburra, Leongatha, Wonthaggi, Cape Paterson and Inverloch:

– Supply enhancement is required within the next few years for Poowong, Loch, Nyora and

Korumburra.

– Future supply requirements for Leongatha are dependent on whether proposed water

savings at Murray Goulburn result in a reduction in demand from South Gippsland

Water‟s reticulated supply. Additional supply would be required by around 2020 if

Murray Goulburn demands remain at current levels.

– A business case is currently underway which is considering the financial costs and

benefits and associated risk profile for two alternative supply strategies for the northern

and southern towns. These include supply from enhancing existing separate South

Gippsland Water headworks or supply from an interlinked system connected to Lance

Creek Reservoir and the Melbourne supply.

– Preliminary outcomes from the business case and this WSDS indicate that the connection

to the Melbourne supply option has the advantage of being more robust to changes in

streamflow under climate change and potential increases in demand under the Local

Growth scenario. It is also more resilient to severe prolonged drought. This option also

potentially improves river health if existing on-stream storages in the Tarwin and Bass

PAGE v

River catchments are decommissioned. Both options were of similar cost at the

preliminary costing stage. A definitive preferred strategy is dependent on the outcomes of

the business case.

– Both options would allow the potential to connect the nearby unserviced towns of Venus

Bay and Tarwin Lower, which would increase South Gippsland Water‟s customer base by

up to 1,000 ML/yr at the end of the 50 year planning horizon.

For South Gippsland Water’s central towns, which includes Dumbalk, Meeniyan, Foster,

Fish Creek, Toora, Port Welshpool, Welshpool and Port Franklin:

– Dumbalk, Meeniyan and Foster have sufficient supply to meet demands at South

Gippsland Water‟s level of service objective for reliability of supply over the 50 year

planning horizon.

– Supply enhancement is required within the next few years for Fish Creek and towns

currently supplied by the Agnes River (Toora, Port Welshpool, Welshpool and Port

Franklin).

– Two alternative supply strategies were considered for the central towns, namely enhancing

existing separate South Gippsland Water headworks or supply from an interlinked system

connecting Foster, Fish Creek and Toora.

– A preliminary assessment indicated that the interlinked system has the advantage of

greater flexibility and robustness to potential future changes in demand at Barry Beach

and provides South Gippsland Water with the option to provide reticulated supply to the

currently unserviced towns south of Fish Creek. These unserviced towns include Sandy

Point, Walkerville, Waratah Bay and Yanakie. A definitive preferred strategy is

dependent on the outcomes of further financial analysis, which is currently being

undertaken by South Gippsland Water.

For South Gippsland Water’s eastern towns, which include Yarram, Port Albert, Alberton

and Devon North:

– South Gippsland Water‟s current program to purchase up to 400 ML/yr of groundwater

licences from existing licence holders for use at its newly constructed bore is expected to

be sufficient to meet South Gippsland Water‟s level of service objective for reliability of

supply over the 50 year planning horizon.

A plan of system wide actions is shown in Table 1, along with specific actions for each group of

towns in Figure 3 to Figure 5.

The WSDS will be reviewed and updated every 5 years to incorporate additional hydrologic data,

changes in demand for water, changes in community expectations and improvements in scientific

knowledge. There are several areas of uncertainty for South Gippsland Water in developing the

WSDS, which will need to be monitored on an ongoing basis.

PAGE vi

Table 1 Action plan – system wide actions

A. Demand Management

1 Reduce uncertainty in current and future estimates of consumer demand through

ongoing monitoring and metering, particularly for major industrial water users

2 Continue current successful water conservation initiatives, including the WaterMap

program for major industrial and rural customers

3 Actively pursue opportunities for the use of treated wastewater to offset potable supply

B. System Management

4 Reduce water leaks and wastage in reticulation systems and water treatment processes

5 Secure dams against leakage and future failures

C. Management for Forward Planning

6 Monitor stream flows and possible climate change

7 Monitor catchments to ensure reliable supply and quality of water

8 Encourage the use of alternative water sources where appropriate

9 Develop long term plan to extend water supply to unserviced towns

10 Monitor demographic trends, and hence potential demand for water, in cooperation with

DSE and local planning authorities

Figure 3 Action Plan for Northern and Southern Towns (preferred option dependent on business case outcomes)

Supply from Existing Separate South Gippsland Water Headworks

Supply from Melbourne

Approx. Timing

Action under Victoria in Future Growth

Action under Local Growth

2012/13 Raise Little Bass Reservoir and connect Korumburrato Little Bass Reservoir.

2016/17 None Upgrade Tarwin R West Branch supply to bulk entitlement limit.

2017/18 Raise Bellview Creek Reservoir whilst dam safety works are undertaken.

~2025 Connect unserviced towns near Inverloch to Lance Creek system.

~2025 None Increase storage at Leongatha by 1000 ML

2025-2039 None Connect Leongatha to Melbourne supply

2034-2039 None Connect Korumburra to Melbourne supply

2040-2047 None Increase supply to Lance Creek from Melbourne

2044-2049 None Connect PLN to Melbourne supply

Approx. Timing

Action under Victoriain Future Growth


2012/13 Connect Poowong, Loch, Nyora and Korumburra to Melbourne supply and decommission water treatment plants. Decommission or seek alternative uses for raw water storages.

2020 None Connect Leongatha to Melbourne supply, decommission Leongatha water treatment plant. Decommission or seek alternative uses for raw water storages.

~2025 Connect unservicedtowns near Inverloch to Lance Creek system.

Increase supply from Melbourne to above 10 ML/d and connectunserviced towns near Inverloch to Lance Creek system.

2052-2058 Increase supply from Melbourne above 10 ML/d.

Further increase supply from Melbourne.

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Figure 4 Action Plan for Central Towns (preferred option dependent on financial analysis outcomes)

Figure 5 Action Plan for Eastern Towns


Supply from Interlinked System

Approx. Timing



2012/13 Construct off-stream storage up to 250 ML at Toora

2012/13 -Obtain bulk entitlement to divert from Hoddle Creek-Raise Battery Creek Reservoir by 2 metres-Construct weir on Hoddle Creek and diversion pipeline

~2025 Connect some or all unserviced towns south of Fish Creek from Foster or from new water source

Approx. Timing Action under Victoria in Future Growth


2012/13 Connect Toora, Foster and Fish Creek treated water systems

~2025 Connect some or all unservicedtowns south of Fish Creek

Connect some or all unserviced towns south of Fish Creek with additional 100 ML off-stream storage at Toora

In response to concretedevelopment

proposal at Barry Beach

Consider increasing off-stream storage at Toora in stages up to 250 ML

Approximate Timing

Action

2011 Continue purchasing groundwater licences up to 400 ML/yr from existing licence holders

PAGE viii

Glossary

This glossary of terms is largely based on the relevant terms from the glossary used by the

Department of Sustainability and Environment for the draft Gippsland Region Sustainable Water

Strategy (DSE, 2010).

Aquifer A layer of underground sediments which holds water and allows water to flow through it.

Augmentation Increase in size and/or number.

Baseflows The component of streamflow supplied by groundwater discharge (or simulated from

other environmental water).

Bulk Entitlement (BE) The right to water held by water corporations and other authorities defined

in the Water Act 1989. The BE defines the amount of water that an authority is entitled to from a

river or storage, and may include the rate at which it may be taken and the reliability of the

entitlement.

Cap An upper limit for the diversion of water away from a waterway, catchment or basin.

Catchment An area of land where run-off from rainfall goes into one river system.

Catchment management authorities (CMAs) Government authorities established to manage

river health, regional and catchment planning, and waterway, floodplain, salinity and water quality

management.

Dead storage Water in a storage that is below the lowest constructed outlet.

Desalination Removing salt from water sources – normally for drinking purposes.

Diversions The removal of water from a waterway.

Domestic and stock Water used in households and for pets and other animals.

Drought response plan Used by urban water corporations to manage water shortages, including

implementation of water restrictions.

Ecosystem A dynamic complex of plant, animal, fungal and micro-organism communities and the

associated non-living environment interacting as an ecological unit.

Effluent Treated sewage that flows out of a sewage treatment plant.

Environmental flow regime The timing, frequency, duration and magnitude of flows for the

environment.

Environmental water reserve (EWR) The share of water resources set aside to maintain the

environmental values of a water system.

EPA Victoria Environmental Protection Authority Victoria.

Estuaries Zones where a river meets the sea, influenced by river flows and tides and characterised

by a gradient from fresh to salt water.

Farm dams Individually owned storages that capture catchment run-off. Also referred to as small

catchment dams.

Floodplain Lands which are subject to overflow during floods. Often valuable for their ecological

assets.

Gigalitre (GL) 1,000,000,000 litres.

Greywater Household water which has not been contaminated by toilet discharge, and can be

reused for non-drinking purposes. Typically includes water from bathtubs, dishwashing machines

and clothes washing machines.

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Groundwater All subsurface water, generally occupying the pores and crevices of rock and soil.

Groundwater management area (GMA) Discrete area where groundwater resources of a suitable

quality for irrigation, commercial or domestic and stock use are available or are expected to be

available.

Groundwater management plans Created for water supply protection areas that have been or are

proposed to be proclaimed under the Water Act 1989 to ensure equitable and sustainable use of

groundwater.

Groundwater management unit (GMU) Either a groundwater management area (GMA) or water

supply protection area (WSPA).

Headworks Dams, weirs and associated works used for the harvest and supply of water.

Inflows Water flowing into a storage or a river.

Instream The component of a river within the river channel, including pools, riffles, woody debris,

the river bank and benches along the bank.

Level of service objectives South Gippsland Water‟s target maximum frequency of restrictions

and the objective to maintain continuous supply to customers without running out of water.

Licensing authority Administers the diversion of water from waterways and the extraction of

groundwater on behalf of the Minister for Water.

Mean Annual Flow (MAF) is the average flow for the individual year or multi-year period of

interest. Mean annual flow is calculated by dividing the sum of all the individual daily flows by the

number of daily flows recorded for the year.

Megalitre (ML) One million (1,000,000) litres.

Non-residential Water use in industry, commercial/institutional buildings, open spaces (parks and

gardens) and the water distribution system.

Outfall The site of discharge of a liquid from a pipe. Applied particularly to the point at which a

sewer discharges to a treatment works or receiving water (such as river, creek or bay).

Passing flow Flows that a water corporation must pass at its reservoirs before it can take any water

for consumptive use.

Perennial stream A stream that flows all year.

Permissible consumptive volume (PCV) The volume of water permitted to be allocated in

discrete groundwater management areas. Previously called permissible annual volumes (PAVs).

Potable Suitable for drinking.

Qualification of rights The Minister for Water declares a water shortage and qualifies existing

water entitlements to reallocate water to priority uses.

Raw water Water that has not been treated for the intended purpose.

Recharge (to groundwater) The process where water moves downward from surface water to

groundwater due to rainfall infiltration or seepage/leakage.

Recycled water Water derived from sewerage systems or industry processes that is treated to a

standard appropriate for its intended use.

Regional River Health Strategy The key strategy for the protection of river values in each

catchment management region in Victoria.

Reliability of supply Represents the annual frequency with which water can be supplied without

the need for water restrictions.

Reservoir Natural or artificial dam or lake used for the storage and regulation of water.

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Residential use Water use in private housing.

Reticulation Network of pipelines used to deliver water to end users.

River basin The land into which a river and its tributaries drain.

Run-off Precipitation or rainfall which flows from a catchment into streams, lakes, rivers or

reservoirs.

Salinity The total amount of water-soluble salts present in the soil or in a stream.

Sewage Wastewater produced from household and industry.

Sewerage The pipes and plant that collect, remove, treat and dispose of liquid urban waste.

Stormwater Run-off from urban areas. The net increase in run–off and decrease in groundwater

recharge resulting from the introduction of impervious surfaces such as roofs and roads within

urban development.

Streamflow management plan Prepared for a water supply protection area to manage the surface

water resources of the area.

Sustainable Diversion Limit (SDL) The upper limit on winter-fill diversions within an

unregulated river sub-catchment, beyond which there is an unacceptable risk to the environment.

Unincorporated areas (UA) Areas with limited groundwater resources which are not defined as

groundwater management areas and do not have a defined permissible consumptive volume.

Unregulated systems River systems with no large dams or weirs to regulate flow and all

groundwater sources.

Water corporations Government organisations charged with supplying water to urban and rural

water users. They administer the diversion of water from waterways and the extraction of

groundwater. Formerly known as water authorities.

Water Supply Protection Area (WSPA) An area declared under the Water Act 1989 to protect

groundwater and/or surface water resources in the area. Once an area has been declared, a water

management plan is prepared.

Water-use licence Authorises the use of water on land for irrigation.

Wetlands Inland, standing, shallow bodies of water, which may be permanent or temporary, fresh

or saline.

Winter-fill licence A licence issued which permits taking water from a waterway only during the

winter months (July-November).

Yield The quantity of water that a storage or aquifer produces. For supply systems in this WSDS it

is defined as the average annual demand at which the level of service objectives for supply are just

met.

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Contents

1. Introduction 17

1.1. About the Water Supply Demand Strategy (WSDS) 17

1.2. South Gippsland Water’s supply systems 17

1.3. Previous long-term water supply planning undertaken by South Gippsland Water 20

1.4. The Melbourne supply connection and South Gippsland Water’s water planning 20

1.5. Climate conditions assumed for the WSDS 21

1.6. Consultation process for preparing the 2010 WSDS 22

2. Long-term Planning Objectives 24

2.1. Introduction 24

2.2. Planning process objectives 24

2.3. Level of service objectives 24

2.4. Defining yield 25

3. Regulatory Framework Governing Current and Future Water Supply28


3.2. Bulk entitlements from rivers 28

3.3. Groundwater licences 30

3.4. Future water supply 31

3.5. Future water supply from rivers and streams 31

3.6. Future groundwater supply 37

3.7. Bulk entitlement from the Melbourne supply system 39

3.8. Stormwater 39

3.9. Reuse of treated effluent 40

4. Water Demand Projections 43


4.2. Types of demand 43

4.3. Current demand 43

4.4. Growth in residential demand 44

4.5. Growth in major industrial demand 46

4.6. Growth in supply by agreement and concessions demand 48

4.7. Summary of demand projections 49

4.8. Unserviced towns 50

4.9. Current demand reduction initiatives 51

4.10. Future demand reduction initiatives 54

4.11. Uncertainties surrounding future demand projections 55

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5. Sustainability Assessment Method for Demand and Supply Options57

5.1. Approach 57

5.2. Assessment criteria and scoring 58

6. Overall Approach to Assessing Demand Reduction and Supply Enhancement Options 65

7. Supply and Demand Projections for Poowong, Loch and Nyora with Current Operation and Infrastructure 67


7.2. Current water supply and demand 67

7.3. Environmental condition 70

7.4. Water supply and demand projections with current operation and infrastructure 71

7.5. Future demand projections 72

7.6. Sensitivity of projections 74

7.7. Additional demand reduction options 75

7.8. Summary of the supply and demand for Poowong, Loch and Nyora with current operation and infrastructure 76

8. Supply and Demand Projections for Korumburra with Current Operation and Infrastructure 77





8.5. Sensitivity of supply to catchment land use change 88


8.7. Summary of the supply and demand for Korumburra with current operation and infrastructure 89

9. Supply and Demand Projections for Leongatha and Koonwarra with Current Operation and Infrastructure 90







9.7. Summary of supply and demand for Leongatha and Koonwarra with current operation and infrastructure 102

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10. Supply and Demand Projections for Wonthaggi, Cape Paterson and Inverloch with Current Operation and Infrastructure 104







10.7. Summary of the supply and demand for Wonthaggi, Cape Paterson and Inverloch with current operation and infrastructure 114

11. Supply and Demand Projections for Unserviced Towns near Inverloch with Current Operation and Infrastructure 115







11.7. Summary of the supply and demand for unserviced towns near Inverloch with current operation and infrastructure 119

12. Strategy for South Gippsland Water’s Northern and Southern Towns120


12.2. Supply from existing South Gippsland Water headworks 120

12.3. Supply from Melbourne 130

12.4. Sustainability Assessment of Options 133

12.5. Strategy Summary 136

13. Supply and Demand Projections for Dumbalk with Current Operation and Infrastructure 139







13.7. Summary of the supply and demand for Dumbalk with current operation and infrastructure 147

PAGE xiv

14. Supply and Demand Projections for Meeniyan with Current Operation and Infrastructure 148







14.7. Summary of the supply and demand for Meeniyan with current operation and infrastructure 156

15. Supply and Demand Projections for Foster with Current Operation and Infrastructure 157







15.7. Summary of the supply and demand for Foster with current operation and infrastructure 164

16. Supply and Demand Projections for Fish Creek with Current Operation and Infrastructure 165







16.7. Summary of the supply and demand for Fish Creek with current operation and infrastructure 175

17. Supply and Demand Projections for Toora, Welshpool, Port Welshpool and Port Franklin with Current Operation and Infrastructure 176




PAGE xv




17.7. Summary of the supply and demand for Toora, Welshpool, Port Welshpool and Port Franklin with current operation and infrastructure 186

18. Supply and Demand Projections for Unserviced Towns South of Fish Creek with Current Operation and Infrastructure 187







18.7. Summary of the supply and demand for unserviced towns south of Fish Creek with current operation and infrastructure 190

19. Strategy for Central Towns 191


19.2. Supply from existing South Gippsland Water headworks 191

19.3. Supply from a linked system 194

19.4. Sustainability assessment of options 196

19.5. Strategy summary 198

20. Strategy for Eastern Towns 200







20.7. Supply enhancement options 211

20.8. Sustainability assessment of options 212

20.9. Strategy summary 212

21. Strategy for Other Unserviced Towns 214

22. Conclusions 215

23. References 219

Appendix A Self-audit checklist 223

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Appendix B Alternative Water Supply Options for Unserviced Coastal Towns and Developments 226

B.1 Summary 226

B.2 Bore water 227

B.3 Rainwater 228

B.4 Greywater 229

B.5 Stormwater 229

B.6 Local desalination of sea water 230

Appendix C Nyora Planning Controls 231

1. Introduction

1.1. About the Water Supply Demand Strategy (WSDS)

The Water Supply Demand Strategy (WSDS) outlines South Gippsland Water‟s strategy for

managing the water supply and demand balance to its customers over the next 50 years. This long-

term view is a component of South Gippsland Water‟s overall planning processes, which includes

planning for drought response, financial expenditure, asset management, water quality and

wastewater. Short-term actions presented in this strategy will feed directly into the Corporation‟s

expenditure program. The strategy also formed the basis of South Gippsland Water‟s input into the

Gippsland Region Sustainable Water Strategy, which considered the needs of other water users

such as irrigators and the environment in a regional context. The WSDS takes into account

regional river health strategies and works within sustainable diversion limits for water resource

development set by the State Government.

This strategy is to be reviewed every five years to take into account changes in consumer demand

and water availability. Actions which are due to take place more than five years into the future can

therefore be reviewed in light of better knowledge when that update takes place. Revision of the

WSDS will be particularly important for current areas of uncertainty, such as the impact of climate

change on available water supplies.

This update to the Water Supply Demand Strategy in 2011 follows on from the previous update in

2007 and now takes into account the effects of the 2006/07 drought year, changes in South

Gippsland Water‟s operation as a result of the drought, the 2006 population census results and

projections, and the potential to obtain a supply from the Melbourne Water Supply System via a

pipeline that connects the desalination plant at Wonthaggi, to be commissioned in 2011, to the

Melbourne supply system. This review is occurring ahead of schedule in order to ensure that South

Gippsland Water‟s planning is in line with these recent developments.

This strategy was prepared in accordance with the Department of Sustainability and Environment‟s

Guidelines for the Development of a Water Supply Demand Strategy (DSE, 2005). These

guidelines are in the process of being updated by DSE, but were not finalised prior to the drafting

of this WSDS.

1.2. South Gippsland Water’s supply systems

South Gippsland Water currently manages ten water supply systems to 21 individual towns, listed

in Table 1-1. A locality map of the towns supplied by South Gippsland Water is shown in Figure

1-1.

Current raw water demand is presented to indicate the relative size of each supply system. The

towns of Poowong, Loch, Nyora, Korumburra, Leongatha and Koonwarra are referred to

collectively as South Gippsland Water‟s “northern towns” and Wonthaggi, Cape Paterson and

Inverloch are referred to as South Gippsland Water‟s “southern towns”. Dumbalk, Meeniyan,

Foster, Fish Creek, Toora, Welshpool, Port Welshpool, Port Franklin and Barry Beach are referred

to as South Gippsland Water‟s “central towns”, whilst “Yarram, Alberton, Port Albert and Devon

North are referred to as South Gippsland Water‟s “eastern towns”.

Table 1-1 Water Supply Systems Managed by South Gippsland Water

Supply System Towns Supplied Current average raw water demand (ML/yr)

(1)

Northern Towns

Little Bass River Poowong, Loch, Nyora 264

Coalition Creek Korumburra 621

Ruby Creek Leongatha, Koonwarra 1,893

Southern Towns

Lance Creek Wonthaggi, Cape Paterson, Inverloch 1,706

Central Towns

Tarwin River East Branch Dumbalk 17

Tarwin River Meeniyan 65

Deep Creek/Foster Dam Foster 140

Battery Creek Fish Creek 136

Agnes River Toora, Welshpool, Port Welshpool, Port Franklin, Barry Beach Port

564

Eastern Towns

Tarra River Yarram, Alberton, Port Albert, Devon North 560

TOTAL 5,966

(1) Estimated at current level of population and industrial development over a long-term climate sequence (typically 40+

years) to account for differences in water demand in wet, average and dry years

Figure 1-1 Locality Map

1.3. Previous long-term water supply planning undertaken by South Gippsland Water

South Gippsland Water‟s area of operation has one of the fastest growing populations in Victoria.

South Gippsland Water has been actively investigating the future water demand and supply balance

in its region over a number of years in order to anticipate and adequately plan for any potential

future water supply shortfalls.

South Gippsland Water examined specific supply augmentation options for those supply systems

that did not meet level of service objectives in 2003 (SKM, 2003b). It then prepared a long-term

water supply planning strategy for all of its supply systems in 2004, including options to supply

unserviced towns (SKM, 2004b). This strategy pre-empted the State Government‟s call for a

WSDS from Victoria‟s water authorities, which was prepared and released by South Gippsland

Water (2007).

South Gippsland Water is also undertaking various investigations in parallel with the WSDS, which

in particular include supply enhancement investigations for connecting to the Melbourne supply,

financial business case modelling of options, and bulk entitlement amendments for some surface

water systems.

1.4. The Melbourne supply connection and South Gippsland Water’s water planning

In 2010 the State Government funded a 10 ML/d pipeline to provide a water supply from the Lance

Creek water supply system (adjacent to the Powlett River near Wonthaggi) to the desalination

construction site. After construction of the desalination plant, which is to be commissioned in

2011, this pipeline will be available to South Gippsland Water to connect the Lance Creek system

to the Melbourne supply system. The Lance Creek system is currently a very reliable source of

water for the towns of Wonthaggi, Cape Paterson and Inverloch. The availability of a connection

to the Melbourne supply system provides increased drought security to these towns, as well as the

potential to connect other less reliable supply systems and currently unserviced towns.

Key to this update of the long-term Water Supply Demand Strategy (WSDS) for South Gippsland

is to consider the opportunity for additional water that connection of South Gippsland Water to the

Melbourne supply system provides. A connection to the Melbourne supply system provides South

Gippsland Water with the option to access a significant volume of water that is not dependent on

rainfall. Given the significant reduction in available supply during the 2006/07 drought and the

subsequent severe restrictions imposed on customers, this alternative source of water would

significantly reduce South Gippsland Water‟s risk to climate variability and climate change.

The approach to this planning study has been to consider future supply options for the northern,

southern and central towns both with and without a connection to the Melbourne supply system.

South Gippsland Water must carefully consider any cost implications associated with being

connected to the Melbourne supply system, and is currently preparing business cases to assess this

issue. The connection to the Melbourne supply system also has implications for South Gippsland

Water‟s water treatment operations. The preferred strategy for the northern, southern and central

towns, and the unserviced coastal towns, will not be known until the business cases are completed.

Therefore South Gippsland Water has developed a dual strategy which allows for the possibility of

either developing local water sources or utilising water from the Melbourne supply system.

1.5. Climate conditions assumed for the WSDS

South Gippsland, similar to many other parts of south-east Australia, has since the late 1990s

experienced the worst prolonged drought on record. The “ongoing low flows” scenario assumes

that long-term climate and streamflow conditions will be similar to those experienced from 1997 to

2009. Figure 1-2 presents historical streamflows for the Tarwin River at Meeniyan, which is the

site of one of the longest recorded streamflow gauging stations in South Gippsland and includes

contributions from streams supplying Korumburra, Leongatha, Dumbalk and Meeniyan. This

figure shows that streamflows from July 1997 to June 2008 were around 44% lower than the long-

term average prior to July 1997. The figure also shows that dry periods have occurred in the past

during the early 1970s and in individual years such as 1982/83. It is arguable that these conditions

are due to natural climate variability and it is noted that the reduction in streamflows over the last

twelve years is greater than the 15% reduction anticipated under medium climate change conditions

by the year 2060.

For the WSDS, South Gippsland Water has planned its demand reduction and supply enhancement

measures on the assumption of medium climate change conditions over the next 50 years, based on

CSIRO‟s climate change projections, as reported in Jones and Durack (2005). These are the basis

of the climate change projections currently used in the Draft Gippsland Region Sustainable Water

Strategy (DSE, 2010). More recent atmospheric modelling has been undertaken by CSIRO as part

of the South East Australia Climate Initiative (SEACI), however those modelling results only

currently extend to the year 2030, which is well short of the planning horizon for the WSDS. South

Gippsland Water will adopt the SEACI modelling results when sufficient guidance is provided by

DSE on the appropriate use of this information over the 50 year planning horizon. Such guidance

is expected in 2011 for all water utilities across Victoria.

South Gippsland Water has also prepared itself for the possibility that the low inflow conditions

observed since the late 1990s could continue indefinitely. The “ongoing low flows” scenario

assumes that long-term climate and streamflow conditions will be similar to those experienced

from 1997 to 2009.

Figure 1-2 Tarwin River at Meeniyan Streamflows

Many of South Gippsland Water‟s supply systems have only small storage capacities relative to

demand and inflows, so South Gippsland Water has also considered the resilience of each supply

system to severe prolonged drought based on a repeat of the 2006/07 drought in consecutive years.

Verdon-Kidd and Kiem (2009) previously illustrated that in south-east Australia the Federation

drought at the start of the 19th century, the World War II drought in the 1930-40s, and the post-

1997 drought were all unique in terms of their underlying climate drivers, and that an alternative

combination of climate conditions could potentially result in a drought which is worse than all

three of these historical events. This scenario of a consecutive repeat of the 2006/07 climate year,

whilst highly unlikely based on historical experience, is therefore nevertheless possible and

plausible. Melbourne Water has used a similar scenario in its augmentation planning, which

involved a repeat of the three dry years from 2004/05 to 2006/07 (DSE, 2008), however the

inclusion of the additional two years prior to 2006/07 is more suited to that supply system which

has much longer storage drawdown periods than exist in South Gippsland.

1.6. Consultation process for preparing the 2010 WSDS

1.6.1. Background 2006 - 09

South Gippsland Water‟s consultation process began in 2006 at the outset of the Water Supply

Demand Strategy project. Using a social research consultant with experience in the water industry

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Annual Flow

Long-term average flow (1955/56-1996/97): 273 GL/yr

Average flow (1997/98-2008/09): 153 GL/yr

and the South Gippsland Region the initial consultation was broadly based including major

industrial customers, local domestic customer groups and landholders.

The consultation process included workshops in Yarram, Wonthaggi and Leongatha, for customers

and information/feedback sessions with relevant local authorities. Over 200 personal invitations

were mailed to known interested customers. Customer participation was encouraged by offering

incentives and covering costs to attend the workshops.

Following the Governments announcement of the Desalination Plant Project at Wonthaggi a range

of new options were available for consideration in the Water Supply Demand Strategy. The advent

of the Desalination Plant Project also called for an updated consultation process with key

stakeholders and customers.

1.6.2. Consultation & Information Process 2009 -10

South Gippsland Water required the development of a comprehensive information and consultation

plan in order to ensure engagement of the widest range of key stakeholder‟s on the 2010 revised

Water Demand Supply Strategy. Communication consultants were engaged to assist in the

preparation and implementation of a Communications Strategy and Action Plan.

In line with the plan presentations, briefings and feedback sessions were undertaken during 2010

with Chief Executive Officers, Councillors of the relevant Shires, other local government

authorities, such as the West Gippsland Catchment Authority, relevant State Government

Departments, peak bodies of the Victorian Water Industry, Economic and Financial Advisors, and

regional community and service groups, across the Region.

The presentations outlined the key elements of the revised Water Supply Demand Strategy

including the significant opportunities provided by the possibility of connection to the Melbourne

water supply leading to the development of the two options that have been closely assessed –

develop existing surface supply systems versus connection to the Melbourne system to supplement

and augment supplies. Feedback from participants at the presentations was sought and has been

included in the Strategy.

As an ongoing part of the communication process further information and consultation sessions are

planned, to present the South Gippsland Water Board endorsed Strategy, to the regions key

stakeholders and community throughout 2011.

2. Long-term Planning Objectives

2.1. Introduction

This section of the WSDS outlines South Gippsland Water‟s objectives in undertaking the WSDS

and the water supply objectives that have been set for customers.

2.2. Planning process objectives

The WSDS is a strategy to ensure a reliable supply of water to South Gippsland Water‟s customers

over the next 50 years. The strategy was prepared within the current guidelines for the WSDS and

within the policy framework for sustainable urban water management outlined in the State

Government‟s White Paper Our Water Our Future. Specifically, this WSDS:

Determines the expected long-term water demand under different demand scenarios for towns

supplied by South Gippsland Water;

Determines the current available supply to meet those demands;

Identifies a range of potential demand reduction and supply enhancement options and selects

and prioritises actions associated with preferred options.

Key aspects of this current WSDS are that it considers:

The total water cycle, including demand reduction and alternative supply options;

Environmental impacts on and risk to the aquatic ecosystems of waterways, wetlands and

aquifers, both now and into the future;

Population growth including “Sea Change Growth” for coastal towns and city fringe

development as shown in a “Local Growth” scenario;

Economic growth for the region‟s primary industries including milk processing at Leongatha

and Korumburra, and attraction of other food processing industries to the region;

Land use changes, both gradual and event based; and

Climate change risk.

The WSDS will lead into subsequent feasibility studies, business case analyses and detailed design

for proposed demand reduction and supply enhancement options. These will be undertaken prior to

seeking Government approvals for the required works. The WSDS provides indicative

sustainability assessments for proposed demand and supply enhancement options. It also forms the

basis of South Gippsland Water‟s position for discussions with other water users in the Gippsland

Region Sustainable Water Strategy.

2.3. Level of service objectives

South Gippsland Water‟s current target level of service objectives for maintaining a reliable supply

to customers are specified as follows:

any level of water restriction should not occur more frequently than 1 year in 10 (i.e. 10 years

in 100)

more severe restrictions (levels 3 and 4 of four stages) should not occur more frequently than

1 year in 15 (i.e. ~7 years in 100).

Stages 1 and 2 restrictions tend to restrict the times at which users can use water for certain

activities, whereas Stages 3 and 4 restrictions tend to affect the activities that can be undertaken at

any time. These level of service objectives for the frequency of restrictions are comparable with

other non-metropolitan urban water authorities in Victoria. South Gippsland Water has already

implemented permanent water saving measures in line with the rest of Victoria.

South Gippsland Water will review target levels of service in the future if the reliability of supply

to its customers can be improved through accessing more reliable sources of water, such as the

Melbourne supply.

2.4. Defining yield

Water supply system yield is the amount of water that can be reliably harvested from a supply

system. Yield can be affected by several factors, such as the amount of rainfall in South Gippsland

Water‟s supply catchments, the mix of water sources in each supply system, the available storage,

operational rules that South Gippsland Water must follow for extracting water and passing

environmental flows, and South Gippsland Water‟s target reliability for providing supply to

customers without restrictions. Yield is defined by the Water Services Association of Australia as

“the average annual volume that can be supplied by a water supply system subject to an adopted set

of operational rules and a typical demand pattern without violating a given level of service

standard” (Erlanger and Neal, 2005). For this Water Supply Demand Strategy, water resource

models for each supply system have been used to estimate how much water could be supplied over

a long-term climate sequence (typically 40+ years) without experiencing restrictions more

frequently than desired (as expressed in Section 2.3) and without running out of water in the most

severe drought over that climate sequence. Yield at any point over the planning horizon is defined

for this strategy as the average annual demand at which the level of service objectives are just met.

Using the average annual demand to define yield allows direct comparison with the future demand

projections to determine when demand exceeds available yield.

An illustration of an example supply and demand curve over the planning horizon is shown in

Figure 2-1. When projected demands exceed the available yield, it does not imply that South

Gippsland Water will no longer be able to supply its customers. For most supply systems it means

that the frequency of restrictions would be expected on average over the long-term to be more

frequent than desired by South Gippsland Water‟s customers. Small deviations below the desired

level of service are likely to be imperceptible to customers. For example, it is unlikely that

customers would be able to perceive a difference if mild restrictions occurred on average in the

long-term 1 year in 9 rather than 1 year in 10. Customers would however be likely to perceive a

difference if restrictions were to occur 1 year in 5, which would be roughly double the desired

frequency of restrictions.

Figure 2-1 Yield and demand over the planning horizon – example only

Where yield is limited by the criterion to not run out of water in the most severe drought, any

further increase in demand above this yield is likely to empty bulk water storages in a severe

drought and contingency supplies could be required. The possibility of this event occurring in any

given year will depend on prevailing climate conditions, but in the long-term will have a low

probability of occurrence. For most supply systems a minimum of 40 years of climate data was

used in the analysis, which would mean that the likelihood of requiring emergency supply

measures is less than 2.5% in any one year. For some supply systems, longer climate sequences

were used where available.

Where water is obtained from more than one supply source, the reported yield is for the combined

water supply system. Where those two supply sources have a different reliability of supply, the

resulting yield will often be greater than the sum of the two individual supply sources, particularly

where the timing of supply shortfalls is complementary. Sources of water that are less responsive

Average annual volume

Time

2009 20592019 2029 2039 2049

Demand

Yieldfrom water resource

modelling over a long-term climate

sequence

Demand for water increases as

population growsYield from supply systems

decreases with climate change

Year in which demand exceeds yield (restrictions start to occur

more frequently than target level of service)

Supply to customers will be regularly restricted in these years without supply

enhancement or demand reduction measures

Supply to customers will rarely be restricted in these

years

or unresponsive to climate, such as groundwater and desalination, will therefore often increase

supply system yield to an extent greater than the sum of the yield from the individual supply

sources.

3. Regulatory Framework Governing Current and Future Water Supply

3.1. Introduction

There are various legislative and regulatory controls when seeking additional sources of water.

This section of the WSDS discusses each of those controls and how they influence the decisions

that South Gippsland Water can make about its future demand reduction and supply enhancement

opportunities. This includes discussion of surface water supply, groundwater supply and

desalination.

3.2. Bulk entitlements from rivers

Bulk entitlements define a water corporation‟s entitlement to take water from water sources such as

rivers, reservoirs or other sources of supply. These entitlements are issued to corporations under

the Water Act 1989. South Gippsland Water currently holds bulk entitlements totalling 14,643 ML,

as shown in Table 3-1. This represents the maximum volume that South Gippsland Water could

harvest from its water sources in any given year, subject to availability. The summer supply from

the Tarwin River West Branch is only available as an interim source of water until 30 June 2015.

Table 3-1 Bulk entitlements held by South Gippsland Water

Source Maximum

annual

volume

(ML/yr)

Maximum diversion

rate (ML/d)

Minimum passing flows

Little Bass River 420 2.7 Minimum of 0.5 ML/d or natural flow

Coalition Creek

storage 1,000

4.8 Minimum of 0.6 ML/d or natural flow

Ness Creek 1.6 Minimum of 0.6 ML/d or natural flow

Bellview Creek 3.0 Minimum of 1.0 ML/d or natural flow

Ruby Creek 2,476 17.3 Minimum of 0.5 ML/d or natural flow

Coalition Creek at

Spencers Road

1,800

6.0 (May-Nov) Minimum passing flow 10 ML/d

Tarwin River West

Branch at

Koonwarra

10.0 (May-Nov)

5.0 (Dec-Apr)*

Minimum passing flow 90-100 ML/d


Lance Creek 3,800 35 100 ML/yr when Lance Creek storage

greater than 3000 ML at 1st December. No

daily minimum passing flow.

Powlett River 1,800 10 As per Table 3-2. Winterfill diversions

only.

Tarwin River at

Dumbalk

100 0.72 No minimum passing flows

Tarwin River at

Meeniyan

200 1.3 No minimum passing flows

Deep Creek 326 3.5 Minimum of 0.2 ML/d or natural flow

Battery Creek 251 1.0 No minimum passing flows

Agnes River 1,617 4.8 Minimum of 1.0 ML/d or natural flow

Tarra River 853 As per Table 3-3. As per Table 3-3.

TOTAL 14,643

*Summer diversion only available until 30 June 2015 as an interim measure

Table 3-2 Powlett River bulk entitlement

Flow in the Powlett River

upstream of offtake, F (ML/d)

Flow available for diversion

(ML/d)

Minimum passing flow (ML/d)

> 17 10 F – 10

12 – 17 5 F – 5

< 12 0 F

Note: F = flow in the Powlett River upstream of the offtake in ML/d.

Table 3-3 Tarra River bulk entitlement

Flow in the Tarra River

upstream of offtake weir, F

(ML/d)


(ML/d)


> 12 6 F – 6

6 – 12 0.5 * F 0.5 * F

3 – 6 F – 3 3.0

< 3 0 F

Note: F = flow in the Tarra River upstream of the offtake weir in ML/d.

3.3. Groundwater licences

South Gippsland Water has groundwater licences for groundwater bores at Leongatha and Yarram.

Details of these groundwater licences are listed in Table 3-4. One of the groundwater bores at

Leongatha is shared with a local landowner. The period of groundwater pumping at Leongatha is

restricted to the periods October to December when storage is less than 75% of capacity, and

March to May when storage is less than 50% of capacity. In the March to May pumping period the

pumping must cease when the storages reach 75% of capacity. South Gippsland Water has

obtained in-principle approval from the licensing authority Southern Rural Water to purchase up to

400 ML/yr of groundwater licences at Yarram for extraction at the South Gippsland Water bore at a

rate of up to 4 ML/d.

Table 3-4 Current groundwater licences

Location Annual licensed volume

(ML/yr)

Maximum extraction rate

(ML/d)

Leongatha Bore S9025900/2 310.25 0.85

Leongatha Bore 138891 (shared) 40.0 0.25

Leongatha Bore S9026806/1 91.25 0.25

Leongatha Bore S9029805/2 273.75 0.75

TOTAL Leongatha Bores 386.4* 2.1

Yarram – Golf course 60 1

Yarram – South Gippsland Water bore Transfer process underway 4

*due to restrictions on the timing of pumping, the maximum annual extraction rate is less than the licensed

volume of 715.25 ML/yr

There is also an emergency supply bore at Dumbalk. Its currently unconfirmed yield of 1.5 L/s or

0.13 ML/d is considered insufficient to improve reliability of supply and it was recommended that

a new deeper bore should be drilled if groundwater was to remain an emergency supply (SKM,

2003a). South Gippsland Water investigated the costs of providing a new deeper bore and

concluded that the high estimated cost was not warranted for its minimal possible future use, and

the preferred option is to include restriction of supply and short term carting of water as an

emergency supply.

3.4. Future water supply

South Gippsland Water has a range of potential future water supply sources available to meet

increases in demand over the planning horizon. The regulatory framework governing these

potential future water supply sources are discussed in turn in the following sections, and include:

Future water supply from rivers and streams (Section 3.5), which includes a discussion of:

– river basin caps on diversion;

– winter sustainable diversion limits from streams;

– streamflow management plans and local management rules for private diversions from

streams;

– heritage rivers which can prevent some water source developments; and

– regional river health strategies, which highlight environmental condition of rivers and

priorities for regional environmental management.

Future groundwater supply (Section 3.6);

Future supply from the Melbourne supply system (Section 3.7);

Future supply from stormwater (Section 3.8); and

Future supply from treated effluent (Section 3.9).

3.5. Future water supply from rivers and streams

3.5.1. River basin caps and Sustainable Diversion Limits

Basin caps limiting total water use in a river basin have been set for all river basins in Victoria.

The South Gippsland Basin is one of the few in Victoria that has remaining entitlements available

prior to the cap being reached. The current cap is set at the Sustainable Diversion Limit, which is

described below and which is not available uniformly throughout the basin. When this cap is

reached in particular rivers, this limits South Gippsland Water‟s access to new resources, but it also

creates a market for water trade which South Gippsland Water could access to obtain entitlements

at the market price. If growth were predicted beyond South Gippsland‟s current bulk entitlement, it

would be prudent to seek to obtain an appropriate bulk entitlement volume before the Sustainable

Diversion Limit is reached.

The State Government has defined sustainable diversion limits for harvesting additional water from

streams. Sustainable diversion limits only apply where a Streamflow Management Plan has not

previously been prepared. Under sustainable diversion limits, new diversion from a catchment can

only occur over winter months (July to October inclusive) and is subject to:

A maximum annual diversion from the catchment – this ensures that the reliability of

winterfill supply is at least 80%.

A maximum diversion rate at any given time from the catchment – this is defined as the

difference between the median winterfill flow exceeded in 50% and 80% of years, computed

over the months July to October.

A minimum flow at which diversions cease - this is defined as the maximum of (i) 30% of the

mean daily flow from July to June and (ii) the median daily flow from July to October that is

exceeded in 95% of years.

The annual volume available for diversion in the SDL catchment containing each of South

Gippsland Water‟s existing offtakes is shown in Table 3-5, along with the maximum diversion rate

in the catchment and the minimum flow threshold. This table does not include any additional

entitlements or licences granted since the SDL database was compiled in 2005, this being the latest

information available. It can be seen from this table that additional flow could be diverted in all

catchments except Lance Creek (Wonthaggi, Cape Paterson and Inverloch supply) and Coalition

Creek (part of Korumburra and Leongatha supply). Ruby Creek and Ness Creek are in the same

SDL catchment at Coalition Creek. These catchments are already developed beyond their

sustainable diversion limit.

The sustainable diversion limit is a precautionary value. The sustainable diversion limit does

not necessarily represent an absolute upper limit on development, but rather it can be used as a

trigger for undertaking more detailed studies under a streamflow management plan (SKM/CRCFE,

2002) or other environmental flow assessment process. This means that South Gippsland Water

could apply to harvest additional water from these catchments, however the granting of any

diversion licences would need to be supported by environmental flow studies that indicate that the

ecology of that particular waterway would not be adversely affected by the diversion.

For the overdeveloped catchments, diversion could occur from the adjacent catchments of Wilkur

Creek and Tarwin River (for Coalition and Ruby Creeks) or Foster Creek (for Lance Creek). A

map of the annual volume available for winter diversion across the region is shown in Figure 3-1,

which highlights some of the potential alternative surface water sources for these over-allocated

catchments. Greater detail in each supply area is shown in subsequent figures.

In some cases, the SDL catchment is larger than the catchment above South Gippsland Water‟s

offtake. This means that even if an SDL volume is available, it does not imply that there is

sufficient streamflow to harvest this volume at every location within the SDL catchment. Further

assessments would be required to confirm that streamflow is physically available for harvesting in

catchments where the SDL area is much larger than the area upstream of the town offtake.

It should be noted that the SDL volumes presented in Table 3-5 are based on information from

2005. These SDL volumes are what is currently available at a local scale, and do not take into

account any uptake of unallocated water that may have occurred since that time, such as South

Gippsland Water‟s Powlett River entitlement and South Gippsland Water‟s amendment to the

Tarwin River bulk entitlement.

For the overdeveloped catchments, opportunity could also exist to purchase entitlements from other

water users within the catchment such as upstream private diverters or catchment farm dams. This

would most likely not trigger an environmental flow assessment if entitlements are traded

downstream (B.Hansen DSE pers.comm. 8/4/2004) and would allow South Gippsland Water access

to water within its existing supply catchments.

Table 3-5 Sustainable diversion limits in SDL catchments containing South Gippsland Water water supply catchments^

Stream SDL

catchment

number

SDL

catchment area

(km2)

Water available for

winter diversion at

SDL catchment

outlet (ML/yr)

Catchment

area at South

Gippsland

Water offtake

(km2)

Water available for

winter diversion at

South Gippsland

Water offtake

(ML/yr)

Maximum

diversion

rate

(ML/d)#

Minimum

flow

threshold

(ML/d)#

Little Bass River 2270001 54 809

7.9 118 19.2 13.2

Bellview Creek 4.14 62

Ruby Ck

2270208 99 -1456

9.0 -132

22.9 19.8 Coalition Creek 0.55 -8

Ness Ck 1.46 -21

Lance Creek 2270105 19 -624 18 -591 5.8 4.5

Tarwin R at Dumbalk 2270211 126 1016 126 1016 29.6 29.6

Tarwin R at Meeniyan 2270213 1071 3577 1067 3564 252.6 178.4

Deep Creek 2270303 36 307 36 307 9.6 8.2

Battery Creek (Fish

Creek)

2270216-

2270215

62 840 2.2 30 40.2 25.8

Agnes River* 2270402 67 567 67 567 20.1 24.6

Tarra River* 2270604 216 69 31 69 37.1 32.4

*Available water at downstream locations is lower than at the diversion location. The lower value at the downstream location is shown in this table. # This is the volume available at the SDL catchment outlet.

^Does not include any reduction in available water due to uptake of licences and bulk entitlements since DSE issued the SDL viewer in 2005

Figure 3-1 Water available for winter diversion across South Gippsland

3.5.2. Streamflow Management Plans and Local Management Rules

Streamflow management plans (SFMPs) govern water sharing rules at a local catchment scale in

rivers with unregulated flows where water use is close to or exceeds water availability. No SFMPs

exist across the South Gippsland Region. Some technical background studies on local ecology and

water supply reliability were undertaken in anticipation of an SFMP for the Tarra River, but the

undertaking of that SFMP has been deferred indefinitely. DSE‟s preferred instrument for

managing unregulated flows is now the use of local management rules, so SFMPs are unlikely to

be prepared in the future.

Local management rules for private diverters are specified in the Agnes River, Albert River,

Bruthen Creek, Franklin River, Tarra River and Tarwin River. These rules developed by Southern

Rural Water list the streamflow triggers at which private diverters are placed on rostering,

restrictions and bans.

3.5.3. Heritage Rivers

The purpose of the Heritage Rivers Act 1992 is to provide protection of public land in particular

parts of rivers and river catchment areas in Victoria, which have significant nature conservation,

recreation, scenic or cultural heritage attributes. The Act specifies whether impoundments or

artificial barriers can be constructed and the degree to which new water diversions are permitted.

There are no heritage rivers in South Gippsland and hence the Act will not restrict water resource

development in the region.

3.5.4. Regional River Health Strategies

South Gippsland Water‟s supply area is covered by two regional river health strategies. The Bass

River catchment is covered by the Port Phillip and Westernport Regional River Health Strategy

(Melbourne Water and PPWCMA, 2005), whilst the remainder of South Gippsland is covered by

the West Gippsland Regional River Health Strategy (WGCMA, 2005). The condition of streams

across the region, as identified from index of stream condition assessments in those river health

strategies, ranged considerably as summarised in Table 3-6. Further information on the condition

of individual river reaches can be found in the river health strategies. The reasons for poor river

health can include factors not directly influenced by water availability, such as the presence of

weeds along river banks. Water availability in Coalition Creek, downstream of Ruby Creek, is

considered a significant issue. Further detail on environmental condition of local waterways is

presented in the description of each supply system in subsequent chapters of the WSDS.

Table 3-6 Stream condition in South Gippsland from river health strategies

River Condition

Bass River Poor to moderate

Lance Creek and Powlett River Very poor to moderate

Tarwin River West Branch Poor to moderate

Tarwin River East Branch Moderate

Coalition Creek (including Ruby Creek) Very poor in lower reach (but better condition in mid

to upper reaches)

Wilkur Creek Moderate

Deep Creek Moderate

Agnes River Moderate to good

Tarra River Moderate to good

Fish Creek (including Battery Creek) Poor

3.6. Future groundwater supply

Groundwater Management Areas (GMAs) are discrete areas where the groundwater resources have

been (or can be) sufficiently developed to warrant careful management, or there is a risk to quality.

Groundwater Management Areas have been defined in many areas throughout Victoria due to the

high level of groundwater development, or potential for development. GMAs cover both a surface

area and an aquifer system, where the aquifer system is defined by a depth interval. For most

GMAs, a Permissible Consumptive Volume (PCV) has been defined. The purpose of a PCV is to

provide the licensing authority (Southern Rural Water) with a limit on groundwater extraction

licences to be issued within a GMA, based on the long term sustainable yield of the aquifer system.

Water Supply Protection Areas (WSPA) are proclaimed under the Water Act 1989 for the purpose

of establishing management plans to ensure both groundwater and surface water resources are

managed in an equitable and sustainable manner. This generally occurs when there is a greater

degree of concern and/or uncertainty about the sustainability of extractions from the aquifer.

Under the Water Act, the Minister would declare a GMA to be a WSPA when necessary, and a

Consultative Committee would be formed to manage the WSPA.

A number of the aquifers in South Gippsland are regulated in Groundwater Management Areas

(GMAs) shown in Figure 3-2. These include:

the Leongatha GMA, managed at all depths

the Yarram WSPA, which includes the management of deep aquifers (>200m)

the Giffard GMA which includes the management of the confined Boisdale Formation aquifer

between 50 and 200m

the Tarwin GMA that includes the management of unconfined aquifers (0-25m).

Figure 3-2 Groundwater management areas in South Gippsland

Southern Rural Water, which issues groundwater licences on behalf of the State Government, is not

currently allocating new licences where current allocations are more than 70% of the permissible

consumptive volume. New licences are not being allocated in the Giffard GMA, which is

overallocated, and the Yarram WSPA. Total groundwater extraction is capped , with licences

being able to be secured by purchase or transfer. Usage is less than the permissible consumptive

volume in the Tarwin and Leongatha GMAs and licences can be obtained for extracting water from

these management areas. South Gippsland Water‟s groundwater licence granted from the

Leongatha GMA in 2010 contained a number of constraints which highlighted the difficulty of

obtaining reliable access to additional groundwater from this GMA. In the Tarwin GMA there is a

risk of saline intrusion and/or contamination by septic tanks due to the concentration of

groundwater bores at Venus Bay.

Outside of GMAs and WSPAs, groundwater usage is low relative to the available aquifer yield and

licences will generally be granted for new extractions.

Technical investigations into groundwater availability, ranging from desktop analyses to drilling

investigations, have been undertaken by South Gippsland Water at Leongatha, Korumburra,

Wonthaggi, Poowong/Loch/Nyora, Toora, and Yarram (SKM, 2006 c,d; SKM 2007 d,e). The

outcomes resulted in a series of groundwater bores being constructed in Leongatha and at Yarram

with suitable water not available at the other locations.

3.7. Bulk entitlement from the Melbourne supply system

As of October 2010, South Gippsland Water holds a bulk entitlement to access supply from the

Melbourne supply system. However the entitlement only comes into effect in July 2012 or the date

at which the interface point with the South Gippsland Water supply system commences operation.

The entitlement allows South Gippsland Water to take up to:

1,000 ML/year to supply Wonthaggi, Inverloch and Cape Paterson;

1,000 ML/year to supply Korumburra; and

3,000 ML/year to supply Leongatha and Koonwarra.

Poowong, Loch and Nyora would be supplied from Korumburra.

The volume that can be taken can be restricted if the Melbourne retail authorities are subject to

water restrictions. Under the bulk entitlement, South Gippsland Water must endeavour to agree on

operational arrangements to enable South Gippsland Water to take water from the Melbourne

supply system, which will help to define the precise reliability of this source of water for South

Gippsland Water and the cost of supply.

3.8. Stormwater

Stormwater harvesting involves capturing rainwater from urban areas for storage, treatment and use

within those urban areas. Stormwater can provide a valuable water resource in areas where water

availability is limited and suitable storage and treatment facilities are available. Stormwater can

only be collected from rainfall events, so stormwater must generally be stored after those events for

use at times when conditions are dry. Harvested stormwater makes up a small proportion of

currently used water resources in Victoria, however it is seen as having the potential to grow as a

water resource in future to alleviate pressure on other traditional sources (DSE, 2010).

Stormwater harvesting schemes for towns have been most successfully implemented when

combined with groundwater storage and/or water treatment through wetlands. The City of

Salisbury in South Australia provides an example of such a scheme (City of Salisbury, 2010). It

established one of the first stormwater harvesting Aquifer Storage and Recovery schemes in

Australia, which involved increasing the amount of recharge to underground aquifers by gravity

feeding or pumping stormwater into local aquifers for later extraction (Department of Water, Land

and Biodiversity Conservation, 2010).

In a similar scheme, South Gippsland Water investigated the feasibility of using water stored in the

disused coal mines at Wonthaggi to augment long-term water supply to Wonthaggi, Inverloch,

Cape Paterson and unserviced coastal towns (SKM, 2006). The mines would be recharged with

stormwater. Water quality testing subsequent to the feasibility study found that the salinity of the

water from the mines would be too poor to make the project feasible.

The use and required quality of stormwater is not specifically regulated in Victoria however the

right to harvest stormwater and to construct stormwater harvesting schemes is subject to some

regulation (EPA Victoria, 2010). Although stormwater is an excellent alternative to drinking water

in many situations, there are human health and environmental risks that must be managed before it

can be used. Depending on the urban area where runoff has been collected, the stormwater may

contain contaminants including pathogens, chemicals and litter. Individuals and organisations

implementing a stormwater harvesting scheme have a duty of care to manage the risk to people and

the environment. The Environment Protection Authority Victoria recommends specific guidelines

compiled by CSIRO (CSIRO, 2006).

In addition to providing a valuable water resource, the collection and treatment of stormwater can

reduce the environmental impact on natural waterways by reducing pollutant loads to those natural

waterways (DSE, 2010b).

3.9. Reuse of treated effluent

Reuse of treated effluent is governed under the Environment Protection Act 1970 with supporting

Guidelines for Environmental Management: Use of Reclaimed Water EPA Publication No. 464.2

prepared in 2003. These documents place limits on the quality of treated effluent required for

specific uses. The draft Gippsland Region Sustainable Water Strategy (DSE, 2010) re-iterated that

treated effluent can be used to substitute potable water supplies but is not suitable for use in

drinking water supplies.

Discharge and reuse volumes from South Gippsland Water‟s urban treatment plants and trade

waste customers are shown in Table 3-7 and Table 3-8 respectively. The total volume available in

2009/10 was around 2.5 GL (excluding trade waste). This figure varies from year to year with

changes in stormwater infiltration to the sewerage network under different climate conditions and

changes in water demand. The discharge quality ranges from Class B (suitable for most

agricultural and industrial applications) to Class C (suitable only for a smaller range of agricultural

and industrial applications such as livestock grazing and golf courses).

South Gippsland Water currently utilises approximately 10% of wastewater from the wastewater

treatment plants for pasture irrigation and the offset of potable water for recreational grounds in the

regional towns. Potential exists for increasing the use of treated wastewater to offset potable mains

water supply usage, supply for agricultural use, supplementing streamflow in streams where water

is extracted for urban use, and for supply to wetlands. There are a number of studies underway to

examine the feasibility of increased reuse of treated wastewater for offset of urban supply, and with

the objective of decommissioning ocean outfalls.

Proposal – South Gippsland Water will pursue opportunities for regional and urban demand

substitution through wastewater and stormwater reuse in all supply systems and continue

developing opportunities for increased agricultural use and agricultural development as they arise.

Table 3-7 Wastewater reused by South Gippsland Water in 2009/10

Wastewater

Treatment

Plant

Discharge

Volume

(ML/yr)

Target

Discharge

Quality

Current Treated

Wastewater Use

Plan for reuse

Korumburra 638 Class B Discharge to Inland Waters. 4-5ML reused from standpipe.

Reuse Water available at treatment plant stand pipe, environmental flow to Powlett River system

Leongatha 547 Class B Discharge to Inland Waters. <1ML reused from standpipe.

Reuse Water available at treatment plant stand pipe. Potential reuse for Golf Club or pasture irrigation, environmental flow to Little Ruby Creek

Cape Paterson 85 Class C Discharge to Ocean Waters

No short term reuse plan due to high cost to provide storage facility and pipeline infrastructure

Inverloch 370 Class C Approx 20-30ML/y for pasture and crop irrigation during summer

Winter flow reuse would require winter balancing storage.

Wonthaggi 567 Class C Discharge to Ocean Waters

Options being explored for long term reuse.

Wonthaggi, Cape Paterson and Inverloch Potential for wetland use for all 3 systems downstream of the outlet junction point

Foster 125 Class C Discharge to Ocean Waters

Proposed additional treatment with pasture irrigation and closure of Outfall

Toora 52 Class C 2-3ML used by Toora Football Club during summer

Scheme proposal for Land discharge underway

Tarraville (Yarram and Port Albert)

101 Class C 100ML/y used for pasture irrigation

Continued pasture irrigation

Welshpool 41 Class B Discharge to Land Scheme underway for pasture irrigation

Waratah Bay 2 Class C Discharge to Land Total reuse on Land

TOTAL 2,528

Table 3-8 Trade Waste Discharges in South Gippsland in 2009/10

Wastewater

Treatment

Plant

Discharge

Volume

(ML/yr)

Target

Discharge

Quality

Current Treated

Wastewater Use

Plan for reuse

Leongatha Trade Waste Murray Goulburn

1,088 Class D Discharged to Venus Bay Ocean outfall

High saline content – non pathogenic , non reusable

Korumburra Trade Waste Burra Foods

66 Partial treatment

before discharge to Korumburra

WWTP

Discharged to Korumburra WWTP

Included in Korumburra WWTP reuse plan

4. Water Demand Projections

4.1. Introduction

South Gippsland Water is expecting growth in demand for water from a number of sources,

namely:

Residential population growth

Industrial and commercial expansion

Servicing of currently unserviced towns

This section of the report sets out the background to the demand projections used in the WSDS. It

includes incorporation of outcomes from the 2006 Census, which were not available at the time of

preparing the 2007 WSDS.

4.2. Types of demand

For the purposes of forecasting growth in demand, total demand has been split into various types.

Different growth rates are applied separately to each type. All demands include unaccounted for

water. The demand components are:

Residential/commercial demand – consists of domestic and non-domestic demand, but

excludes major industrial customers. It includes some rural tappings.

Major industrial demand – consists of major industrial customers such as Murray-Goulburn,

Burra Foods, Esso, the Poowong Abattoir and Tabro Meats.

Supply by agreement and concessions – includes customers such as municipal parks and

gardens, and rural tappings supplied by agreement. Concession holders are defined such as

churches, scout halls, not for profit groups, etc.

Environmental demand, which is provided for by South Gippsland Water in minimum passing

flows under bulk entitlements previously described in Section 3.2 and water not diverted or

captured by South Gippsland Water.

Urban demand is assumed to grow in proportion to population. Growth in major industrial demand

is considered on a case by case basis. No growth is assumed for supply by agreement and

concession holders.

4.3. Current demand

Current demand for water in South Gippsland Water‟s supply systems is summarised in Table 4-1.

The figures in this table represent the average annual supply from water sources and include losses.

South Gippsland Water currently extracts around 6.0 GL/yr of raw water, of which 44% is used to

supply residential customers, 35% supplies major industrial/commercial customers, 11% is for

stock and domestic customers and 10% is utilised across South Gippsland Water‟s water treatment

plants.

Table 4-1 Current average demand from supply sources(1)

Supply System Towns Currently Supplied

Urban residential

plus concessional

(ML/yr)

Urban non-residential

including major industrials

(ML/yr)

Stock and domestic (ML/yr)

Treatment plant usage

(ML/yr)

Total raw water

demand (ML/yr)

Northern Towns

Little Bass River Poowong, Loch, Nyora 111 89 40 24 264

Coalition Creek Korumburra 409 178 15 19 621

Ruby Creek Leongatha, Koonwarra 583 1,067 18 225 1,893

Southern Towns

Lance Creek Wonthaggi, Cape Paterson, Inverloch 1,120 240 227 119 1,706

Central Towns

Tarwin River East Branch

Dumbalk 13 2 2 0 17

Tarwin River Meeniyan 48 3 12 2 65

Deep Creek/Foster Dam

Foster 74 20 36 10 140

Battery Creek Fish Creek 19 22 83 12 136

Agnes River Toora, Welshpool, Port Welshpool, Port Franklin 162 223 123 56 564

Eastern Towns

Tarra River Yarram, Alberton, Port Albert, Devon North 325 131 82 22 560

TOTAL 2,863 1,975 638 490 5,966

(1) Estimated at current level of population and industrial development over a long-term climate sequence (typically 40+

years) to account for differences in water demand in wet, average and dry years

Estimates of demand are based on a combination of bulk meter and property meter data, with

adjustments made for longer term climate variability.

4.4. Growth in residential demand

Growth in residential demand is initially based on the Victoria in Future population projections,

produced by Victorian State Government (DPCD, 2010). Information is available on a statistical

local area (SLA) basis for the period 2006 to 2026, for larger statistical divisions for the period

2006 to 2036 and for regional Victoria for the period 2006 to 2056.

SLA population growth data was used to calculate the projected demands in accordance with DSE

guidelines for the WSDS. There are five SLAs within the area supplied by South Gippsland Water,

as shown in Table 4-2. Each demand centre was assumed to have the same growth rate as the SLA

in which it is located. The assigning of towns to each SLA was determined using the Australian

Bureau of Statistics website (www.ausstats.abs.gov.au).

SLA population growth projections are only available to 2026. For the period 2027 to 2036 it was

assumed that population in each of the SLAs changed at the same rate as that for the Gippsland

Statistical Division and from 2037 to 2056 at the same rate as regional Victoria.

Figure 4-1 shows the projected growth rates for each of the SLAs and regional Victoria. It can be

seen that South Gippsland (East) and Wellington (Shire) SLAs have a predicted decline in

population. In contrast, the Bass Coast and South Gippsland (Central) SLAs are predicted to

experience growth which is above the regional rate.

Table 4-2 Towns Located within Statistical Local Areas

Statistical Local Area Towns supplied by South Gippsland Water within

Statistical Local Area

South Gippsland Shire – Central Leongatha, Koonwarra, Meeniyan

South Gippsland Shire – East Toora, Welshpool, Port Welshpool, Port Franklin,

Dumbalk, Fish Creek, Foster

South Gippsland Shire – West Korumburra, Poowong, Loch, Nyora

Bass Coast Shire Balance Wonthaggi, Cape Paterson, Inverloch

Wellington Shire – Alberton Yarram, Alberton, Port Albert, Devon North

http://www.ausstats.abs.gov.au/

Figure 4-1 – Victoria in Future population growth rates for the South Gippsland region

Comparison against previous demand projections, which were based on the 2001 census, is

included within the discussion of each supply system. Victoria in Future growth in household

numbers were also considered, however growth in number of households does not cover the full

planning period of 50 years.

A higher alternative growth scenario, referred to as the Local Growth scenario, is presented for all

supply systems to test the impact of higher growth and associated water requirements. This Local

Growth scenario also takes into account the possibility of higher growth within urban centres

relative to surrounding areas within a statistical local area.

4.5. Growth in major industrial demand

Growth in industrial demand has been considered for two scenarios. The Victoria in Future

population growth scenario has been coupled with South Gippsland Water‟s estimate of future

industrial demand based on best available information from those industrial water users. For the

Local Growth scenario, South Gippsland Water provides for possible higher level industrial

demands. Table 4-3 summarises the assumed major industrial demands for the two scenarios.

Long-term growth in major industrial demand is difficult to predict. Estimates of growth in major

industrial demand are generally not forthcoming from major industries because their planning

horizons are relatively short compared with the 50 year planning horizon of this Water Supply

-1.0%

-0.5%

0.0%

0.5%

1.0%

1.5%

2.0%

2.5%

3.0%

3.5%

2005 2010 2015 2020 2025 2030 2035 2040 2045 2050 2055

Perc

en

tag

e c

han

ge p

er

year

Year

South Gippsland Shire - Central

South Gippsland Shire - East

South Gippsland Shire - West

Bass Coast Shire Balance

Wellington Shire - Alberton

Gippsland Statistical Division

Regional Victoria

Demand Strategy. Technological developments also play a major part in the ability of major

industrial customers to reduce water consumption, which are difficult to predict as well.

Demand for water by Murray Goulburn at Leongatha is not expected to increase in line with

production increases over the coming decades because it is anticipated that growth in demand for

water will be met by improving water use efficiency within the processing plant. Murray

Goulburn, with funding support from the State Government, has embarked on a 10 year, $135

million upgrade of its plant to improve efficiency of operations and to enable new products to be

manufactured. Correspondence with Murray-Goulburn in 2008 indicated that it was anticipated

that there would be a net reduction in demand for water from South Gippsland Water of around 370

ML/yr by 2009/10, with the potential for a further 220 ML/yr reduction by 2012/13. The

anticipated reduction of 370ML/yr in 2009/10 was not achieved. South Gippsland Water‟s role in

planning for the future needs of the Leongatha water system must consider and be cognisant of

possible future water requirements of such a significant water user as Murray-Goulburn. South

Gippsland Water is of the view that there are significant risks that Murray Goulburn will not

achieve its water savings targets, and the local growth demand scenario for Leongatha assumes

Murray Goulburn water demands will remain at current levels. The uncertainty surrounding future

long-term demand for Murray Goulburn means that South Gippsland Water will continue to

communicate with Murray Goulburn about their ongoing water requirements.

At Barry Beach in the Agnes River supply system, there has in recent years been a concept

proposal to construct a brown coal to urea plant with associated residential and commercial

development. The South Gippsland Shire Council (pers.comm. Jan 2011) advises that this proposal

is not currently active. However, from a longer term water resource planning perspective, and also

considering the potential for additional future water use associated with possible development of

Barry Beach port facilities, a future demand of 2 ML/wk (104 ML/yr) has been assumed. This is in

line with water resource investigations in 2008 (SKM, 2008a). For the purposes of this strategy,

this increase in demand has been assumed to occur in 2020. Further details about the associated

developments are currently uncertain and have not been explicitly included in the major industrial

demand forecasts.

No further growth in major industrial demand is anticipated in the remaining supply systems at the

current time. This includes assuming that major industrial demand will not alter due to climate

change.

Table 4-3 Major industrial demand assumptions

Supply system Major industrial demand under

Victoria in Future demand scenario

Major industrial demand under Local

Growth demand scenario

Northern Towns

Poowong, Loch, Nyora 89 ML/yr over planning horizon 89 ML/yr currently.

Steadily increased to 230 ML/yr by the year

2060 for miscellaneous additional use

Korumburra 178 ML/yr over planning horizon 178 ML/yr currently

Increased to 196 ML/yr in 2015 (+10%)



For miscellaneous additional use

Leongatha 1067 ML/yr currently

Decreased to 847 ML/yr in 2010/11

Decreased to 627 ML/yr in 2012/13 in

line with Murray Goulburn’s anticipated

savings

1067 ML/yr currently

Decreased to 1000 ML/yr in 2010/11

assuming Murray Goulburn savings not fully

realised

Increased to 1500 ML/yr in 2025/26 for

increase due to new industrial water user(s)

or step change in water requirement for

Murray Goulburn

Southern Towns

Wonthaggi, Cape

Paterson, Inverloch

240 ML/yr over planning horizon 240 ML/yr currently




For miscellaneous additional use

Central Towns

Toora (Barry Beach) 223 ML/yr currently

223 ML/yr currently

Increased to 327 ML/yr in 2019/20 for Barry

Beach development

All other systems Current demand Current demand

4.6. Growth in supply by agreement and concessions demand

Growth in supply by agreement and concession holders was assumed to be zero for most supply

systems. This was based on identification of the end use of water and discussions with a sample of

those water users by Consulting Environmental Engineers, as noted in South Gippsland Water

(2007).

The exception to this is the Fish Creek system, where the Local Growth Scenario includes an

allowance for a potential increase in demand of 50 ML/yr from rural customers. Demand for water

from these rural users has decreased significantly in recent years due to South Gippsland Water‟s

WaterMap Initiative, which assists farmers in developing on-farm water supply in preference to

reliance on supply from South Gippsland Water. These rural customers could nevertheless need to

supplement their on-farm supplies in a drought year, which could see their demand for supply from

South Gippsland Water return to a level similar to that seen prior to the implementation of the

WaterMap initiative.

4.7. Summary of demand projections

The anticipated growth in demand for South Gippsland Water‟s supply systems based on Victoria

in Future (ViF) predicted growth rates for the next 50 years is summarised in Table 4-4, whilst the

Local Growth scenario demands are listed in Table 4-5. Any sensitivity analyses on these growth

rates, including the potential effect of climate change, are discussed in the section on each supply

system in this report. Total demand for raw water under this Victoria in Future scenario would be

expected to increase from the current 6.0 GL/yr to around 8.0 GL/yr, whilst for the Local Growth

scenario it is expected to increase to around 11.6 GL/yr.

Table 4-4 Victoria in Future long-term average annual demands for the year 2058


Urban residential

plus concessional

(ML/yr)



(ML/yr)


Treatment plant

utilisation (ML/yr)

Total raw water

demand (ML/yr)

Northern Towns

Little Bass River Poowong, Loch, Nyora 168 89 40 29 326

Coalition Creek Korumburra 615 178 15 25 833

Ruby Creek Leongatha, Koonwarra 877 627 18 206 1,728

Southern Towns

Lance Creek Wonthaggi, Cape Paterson, Inverloch 2,860 240 227 229 3,556

Central Towns


Dumbalk 13 2 2 0 17

Tarwin River Meeniyan 67 3 12 3 84


Foster 76 20 36 10 142

Battery Creek Fish Creek 20 22 83 12 137

Agnes River Toora, Welshpool, Port Welshpool, Port Franklin 166 223 123 57 569

Eastern Towns

Tarra River Yarram, Alberton, Port Albert, Devon North 290 131 82 21 524

TOTAL 5,152 1,535 638 592 7,916

Table 4-5 Local Growth long-term average annual demands for the year 2058


Urban residential

plus concessional

(ML/yr)



(ML/yr)


Treatment plant

utilisation (ML/yr)

Total raw water

demand (ML/yr)

Northern Towns

Little Bass River Poowong, Loch, Nyora 280 230 40 54

605

Coalition Creek Korumburra

848 214 15 33

1,110

Ruby Creek Leongatha, Koonwarra 1209 1500 18 368

3,096

Southern Towns

Lance Creek Wonthaggi, Cape Paterson, Inverloch 4,140 312 227 229

4,908

Central Towns


Dumbalk

18 2 2 0

22

Tarwin River Meeniyan

100 3 12 4

118


Foster

104 20 36 12

172

Battery Creek Fish Creek

27 22 133 18

200

Agnes River Toora, Welshpool, Port Welshpool, Port Franklin 228 327 123 75

753

Eastern Towns

Tarra River Yarram, Alberton, Port Albert, Devon North 367 131 82 24

605

TOTAL 7,321 2,761 688 817 11,589

4.8. Unserviced towns

For unserviced towns, per lot residential demand consumption was assumed to be as per a previous

demand study by GHD (2003), with the exception of Tarwin, for which per lot consumption was

reduced from 1.2 kL/d/lot to 0.5 kL/d/lot. The number of lots at existing unserviced towns has

been updated using the 2006 census information, where available. Similar to the residential growth

for serviced towns, growth in demand for water for unserviced towns was based on Local Growth

rates. No further growth was assumed for major lot developments. The demand for water from

unserviced towns is currently estimated at around 680 ML/yr, as shown in Table 4-6. This demand

is expected to increase to 1,140 ML/yr by year 2058 due to Victoria in Future population growth

and up to 1,610 ML/yr under Local Growth population projections. There remains much

uncertainty about what future impact unserviced towns may have on existing supply systems. It

may well be that innovative approaches to how additional water is provided to these existing

communities will result in water requirements being much less than assumed in this study. From a

supply planning perspective, the ability to be able to supply this potential additional water

requirement has been assessed.

Table 4-6 Unserviced towns and future potential developments

Town or development No. of lots Estimated

Current

Demand

(ML/yr)

Estimated

year 2058

Victoria in

Future

demand

(ML/yr)

Estimated

year 2058

Local Growth

demand

(ML/yr)

Bena 54 19 29 48

Tarwin 12 2 3 4

Venus Bay - existing 1,436 261 667 965

Tarwin Lower 92 17 43 62

Harmers Haven 65 12 31 44

Walkerville 167 43 44 61

Waratah Bay 110 28 29 39

Sandy Point 633 162 166 228

Yanakie 100 26 27 37

Greenmount 35 15 13 17

Won Wron 27 12 11 14

Woodside 55 24 21 27

Woodside Beach 46 20 18 23

Robertson’s Beach 46 20 18 23

Manns Beach 20 5 4 6

McLoughlins Beach 50 13 12 15

TOTAL 2,948 679 1,136 1,613

4.9. Current demand reduction initiatives

South Gippsland Water is currently undertaking measures which are expected to result in per capita

demand reduction over time. South Gippsland Water is part of the savewater!TM

alliance through

the Victorian Water Industry Association, which represents all of Victoria‟s water authorities.

Details of the savewater! TM

initiative can be found at http://www.savewater.com.au. The site

provides information on water conservation, runs competitions to win water conserving products

and provides access to suppliers of water conserving products.

For estimating the effect of demand reduction initiatives, South Gippsland Water relies upon the

detailed demand information derived from Melbourne‟s end-use model, which models property

scale demand by considering the in-house and external water use of each property (WaterSmart,

2006a). It is acknowledged that there are some differences between consumer behaviour in

http://www.savewater.com.au/

Melbourne and South Gippsland, however given the high degree of uncertainty surrounding

demand reduction forecasts, this adoption of technical information from Melbourne with justifiable

adjustments is considered appropriate.

In recent years, water conservation efforts by the water utilities and the Victorian Government have

targeted all major aspects of residential water use with an emphasis on education and behaviour

change. A rebate scheme for water conservation products has been operating since January 2003,

which is currently known as the Water Smart Gardens and Homes Rebate Scheme. The most

noteworthy regulatory changes affecting residential indoor water use have been:

The introduction of a mandatory water efficiency labelling for appliances (commencing 2006)

under the national Water Efficiency Labelling and Standards Scheme (WELS);

The introduction of rising block tariffs, which result in higher charges for high water users;

and

The Five Star Home standards which require all new homes in Victoria to have water efficient

showerheads, tapware, a pressure reducing valve where mains pressure is over 50 m, and either

a solar hot water heater or a rainwater tank connected to the toilet (or equivalent saving

through a dual pipe system).

Outdoor water use has been targeted through the introduction of permanent water saving measures,

which include the requirement for a trigger nozzle on hoses, restricted times for garden watering,

no hosing of paved areas and notification to be given to South Gippsland Water when filling a new

pool. These Statewide measures are estimated to have resulted in a 2% reduction in total demand

(TWGWSA, 2005).

South Gippsland Water has an active program promoting water conservation through local

measures. This includes:

Newsletters to customers accompanying each rate notice;

Regular press releases;

Displays and presentations at local community events;

Schools education program;

Regular meetings with high water consumption users;

Grants to community groups for installation of facilities to reduce potable water demand;

Interest free loans to rural customers for installation of water saving measures to reduce

summer demand; and

Consultation with issues and advisory based community groups.

A per capita demand reduction of 22% has been achieved in Melbourne over the last decade,

however some of this demand reduction is due to recent water restrictions and hence a 15% per

capita demand reduction is expected to be achievable when restrictions are lifted (Watersmart,

2006). This reduction includes water savings by industry, government and households.

WaterSmart attributes this to water conservation programs, water pricing reform, water audits with

major industrial water users (WaterMap program), the five star building standard, permanent water

saving measures, water saving garden centres, savewater.com alliance, leak control programs and

the national water efficiency labelling scheme. South Gippsland Water introduced permanent

water saving measures in 2005/06, which are estimated to have resulted in a 2% reduction in

demand (TWGWSA, 2005). For the remaining water saving measures, it could be argued that

household disposable income, water corporation revenue and access to information are lower in

regional areas than in Melbourne, so these water savings could be expected to lag those achieved in

Melbourne. Quantifying this lag is difficult, hence it has been conservatively assumed that existing

demand reduction measures will merely serve to maintain existing per capita demand, similar to

what has been assumed in Melbourne.

Per capita residential demand in South Gippsland is low because the climate is wetter than other

parts of Victoria and because many dwellings are only occupied during the summer months. South

Gippsland Water‟s average annual household consumption, reported to the Essential Services

Commission in 2009/10 (ESC, 2010), was 119 kilolitres per household per year, with 68 kilolitres

per capita per year for residential water use by the permanent population. This equates to 186 litres

per capita per day for permanent residents.

For the purposes of enabling broad comparisons over time and with other regions of Victoria, “per

capita demand” has been calculated using the definition in the Central Region Sustainable Water

Strategy, which includes industrial water use. Most towns in South Gippsland have a high

proportion of major industrial water use and some rural water use, which artificially inflates

estimates of per capita demand in South Gippsland when using this method of calculation relative

to other regions of Victoria. Estimating per capita demands in South Gippsland is also problematic

because of the difficulty in accurately assessing the population being serviced. The estimate of

population from census information is only collected in winter and therefore significantly

underestimates peak summer and Easter populations, which swell due to an influx of tourists to the

region. The population at Inverloch, for instance, can increase significantly during peak holiday

periods. Per capita demand estimates using census population data result in an overestimate of per

capita demand. The 2006 winter population serviced by South Gippsland Water is estimated from

2006 census data to be approximately 22,900. If a seasonally weighted population of double the

winter population is adopted (which may still be an underestimate in some towns), per capita

demand would be 360 litres per capita per day, which is within the 300-400 litre per capita per day

range observed by other water corporations, despite South Gippsland Water‟s high industrial water

demand.

Estimating a change in per capita demand over time is equally problematic without knowledge of

changes in seasonally weighted populations. This is because a change in winter population does

not necessarily translate directly into a change in summer population, which is affected by the state

economy (influencing disposable income and therefore travel decisions), weather conditions and

accommodation capacity.

It is clear that demands in a number of South Gippsland Water‟s supply systems have decreased

significantly in the last three years since the 2006/07 drought. Some of these shifts are attributable

to specific events, such as step changes in major industrial demand, however most are more likely

to be a result of demand management actions being undertaken by South Gippsland Water

including more permanent shifts in customer water using patterns following in some cases

extended restriction periods. The magnitude of these shifts is discussed in the sections of this

report dealing with each supply system.

4.10. Future demand reduction initiatives

South Gippsland Water will actively pursue demand reduction in each supply system. South

Gippsland Water has set itself a demand reduction target in line with State Government targets set

for other water authorities across Victoria of:

A 25% reduction in per capita demand by the year 2015 relative to 1990s average demand; and

A 30% reduction in per capita demand by the year 2020 relative to 1990s average demand.

Assuming that the 22% reduction in per capita demand has already been achieved in South

Gippsland, South Gippsland Water would require a 3% reduction in per capita demand from its

customers by the year 2015 and an 8% reduction in per capita demand by the year 2020 in order to

reach this target. This includes the 2% reduction in demand due to the previous introduction of

permanent water saving measures.

A range of actions by South Gippsland Water and the State Government will be required to meet

these targets. It is anticipated that the majority of these actions would be driven by the State

Government and Melbourne‟s urban water utilities. Specific actions by South Gippsland Water

include the following:

South Gippsland Water will continue to work with its major customers to reduce the water use

of those major customers.

South Gippsland Water will continue to keep abreast of technological developments in water

saving measures currently being investigated by Melbourne‟s urban water utilities through

South Gippsland Water‟s membership of the Victorian Water Industry Association.

South Gippsland Water is supported by the Victorian State Government‟s ongoing water saving

programs, such as the WaterMap, Water Smart Gardens and Homes Rebate Scheme, Showerhead

Exchange Program and Trigger Nozzle Exchange Program. Target 155, which encourages

Melbourne‟s water users to use less than 155 litres per person per day, has also been publicised

outside of Melbourne through print, radio, television and internet media that extend beyond

Melbourne.

The extent to which demand reduction targets are achievable in any given year will be influenced

by the age profile of assets, particularly in small supply systems, of which South Gippsland Water

operates several. As assets such as pipelines approach the end of their useful life, they are more

likely to leak or burst, increasing water losses. In larger systems such as the Ruby Creek system

supplying Leongatha, this will be balanced to a greater extent by having a range of assets of

different ages at any given time, meaning that there is unlikely to be a large fluctuation in leakage

rates for these systems.

Measuring the effectiveness of these actions against South Gippsland Water‟s target will be based

on measuring the change in the per capita demand from the 397 litres per capita per day value

presented in the 2007 WSDS to 385 litres per capita per day by 2015 and 365 litres per capita per

day by 2020. These targets are based on an assumed seasonally weighted population of double the

winter population. Meeting these targets also assumes that the seasonally weighted population

increases in proportion to the increase in winter population for the period over which the targets

have been set. When measuring these targets, an allowance will need to be made for any changes

in water use from major industrial customers that is associated with changes in production. Water

demand trend information, presented in subsequent chapters of the WSDS and the current estimate

of South Gippsland Water‟s per capita (residential, rural and industrial) demand of 360 litres per

day, suggests that South Gippsland Water and its customers have already reached these future

targets.

4.11. Uncertainties surrounding future demand projections

There are many uncertainties surrounding future demand projections and hence these figures

should be regarded as a guide to be reviewed as information is collected for subsequent WSDS

updates every five years. There are uncertainties in population growth, which is largely affected by

local, interstate and international migration, uncertainties in future household sizes, lot sizes and

the availability and uptake of water saving technologies.

Changes in social patterns, including smaller families and people living longer mean that the

number of persons per household continues to decline. This impacts on water use, because houses

with lower occupancy rates use more water per person. For example, in Melbourne a single person

house typically uses 250 L/cap/day, a two person house uses around 200 L/cap/day and a three

person house uses around 170 L/cap/day. Thus the trend to fewer persons per household translates

to an increased demand for water per head of population. Running against this trend is the

tendency towards smaller lot sizes and apartment dwellings, which have a much lower outdoor

water use than a detached house.

Towns served by South Gippsland Water have a relatively high proportion of households with a

single, elderly person. When these houses are turned over to families of two or more persons,

water use per property would be expected to increase.

There are also many uncertainties surrounding future commercial / industrial demand projections,

and for this reason as well it will be necessary to update the WSDS at least every 5 years.

5. Sustainability Assessment Method for Demand and Supply Options

5.1. Approach

There are a range of different demand reduction and supply enhancement options that are available

for individual supply systems. This section provides an overview of the method used to assess

options against a range of economic, environmental and social criteria to enable broad scale

comparison between options.

The assessment criteria help to identify critical potential impacts of each option and provide early

warning of potential conflicts or opportunities presented by the option. The outputs of this

assessment can be used to better inform the decision making process, but it does not provide a

definitive answer of which is the best option. The assessment criteria and method developed for

the Sustainable Water Strategies has been employed in this assessment (Table 5-1). These criteria

and scoring systems were developed by the Department of Sustainability and Environment through

extensive consultation with water authorities and have been adopted for WaterSmart and the

Eastern Water Recycling Proposals as well as the Central Region Sustainable Water Strategy.

An additional financial indicator known as the long-run marginal cost has been included in the

analysis to align the outputs from the WSDS with South Gippsland Water‟s Water Plan on pricing

to the Essential Services Commission.

The sustainability assessments for the demand reduction and supply enhancement strategies shown

in subsequent sections of the WSDS have been prepared for conceptual assessment only. South

Gippsland Water will be undertaking functional design, environmental analysis and heritage studies

to further assess sustainability impacts at the appropriate time to obtain the relevant Government

approvals for demand reduction and supply enhancement works.

Table 5-1 Assessment Criteria

Criteria Metric

Economic

Long run marginal cost (LRMC)* $/ML

Net Present Cost $/ML

Effect on GDP (local) and development Estimated effect on local GDP

Environmental

Greenhouse Gas Emissions Average Kg CO2 equivalent per ML per Year

Impact upon environmental flow objectives Estimated relative impact

Impact on surface, ground and marine water quality

Estimated relative impact

Impact on terrestrial ecosystems Estimated loss or gain of significant ecological vegetation classes

Social

Acceptability Estimated degree of opposition or acceptance by the local community

*Duplicate financial indicator required for input to Water Plan for Essential Services Commission.

5.2. Assessment criteria and scoring

All criteria are scored on a scale from -5 to +5, where -5 generally represents a relatively negative

impact or cost and +5 generally represents a relatively high degree of benefit. Scores around 0 are

generally neutral impacts or mid-range costs.

-5 -4 -3 -2 -1 0 1 2 3 4 5

Details of the scoring system for each indicator are described below.

5.2.1. Net Present Cost

The net present cost is a financial assessment of the option. The values included as part of this

assessment have been calculated based on potential volumes of recoverable water together with the

estimated capital and operating and maintenance costs over a 50 year period. The figures represent

the Net Present Cost (5.8% discount rate) divided by the total volume generated by the option over

the 50 year period. Scoring is identical to that described in the CRSWS.

High cost Cost neutral High benefitHigh cost Cost neutral High benefit

Score Descriptor

-5 >$950/ML

-4 $850-950/ML

-3 $750-850/ML

-2 $650-750/ML

-1 $550-650/ML

0 $450-550/ML

1 $350-450/ML

2 $250-350/ML

3 $150-250/ML

4 $50-150/ML

5 <$50/ML

5.2.2. Effect on Local Gross Domestic Production (GDP)

GDP, a measure of the total value of produced goods of a region, is considered to be broadly

representative of the economic flow-on benefits (such as employment) derived from additional

water being made available for a major industry (e.g.: irrigated agriculture). For the purposes of

this assessment the direct (or first order) regional economic impacts, that is those felt outside the

South Gippsland Water region are considered to be negligible for each option, hence this criteria

has been re-interpreted as effect on Local GDP.

The criteria has been scored according to the anticipated increase or decrease in GDP derived from

the allocation of the water to new (not existing) agriculture. Compensating „flow-on‟ effects to

other regions or industries have not been included nor has the indirect benefits and costs passed to

society (e.g. existence values relating to environmental quality). In practice, this comes down to

whether the option makes new water available for irrigated agriculture within the region ( a

positive impact) or alternatively, results in less water available for irrigated agriculture. The base

case is assumed to be no impact on the status quo (zero). Scoring is identical to that described in

the CRSWS.

Score Descriptor

-5 Extreme negative impact on local GDP (25% immediate output reduction for major industry)

-4 Significant negative impact on local GDP (10% immediate output reduction for major industry)

-3 Moderate negative impact on local GDP (25% immediate output reduction for minor industry)

-2 Small negative impact on local GDP (10% immediate output reduction for minor industry)

-1 Marginal negative impact on local GDP (negative impact to potential growth opportunities to minor or major industry)

0 Insignificant change to net regional output

1 Marginal increase in local GDP (positive impact to potential growth opportunities for minor or major Industry)

2 Small increase in local GDP and employment (10% Immediate output expansion for minor industry)

3 Moderate increase in local GDP and employment. Minor Industry; 25% Immediate output expansion

4 Significant increase in local GDP and employment. Major Industry; 10% Immediate output expansion

5 Extreme increase in local GDP and employment. Major Industry; 25% Immediate output expansion

5.2.3. Greenhouse Gas Emissions

This indicator reflects the estimated emissions (kg of CO2 equivalent) per ML, based on the energy

(assumed to be sourced from Victorian Brown coal) consumed in Operations and Maintenance of

each option since this is assumed to be the major source of greenhouse gas emissions. It does not

include the greenhouse gas emissions incurred in the construction or decommissioning stages of

each option, but may take into account the potential greenhouse emissions associated with irrigated

agriculture. Scoring is identical to that described in the CRSWS.

Score Descriptor

-5 15,000 Kg/CO2e/ML/yr

-4 10,000 - 14,999 Kg/CO2e/ML/yr

-3 5,000 – 9,999 Kg/CO2e/ML/yr

-2 1,500 - 4,999 Kg/CO2e/ML/yr

-1 700 – 1,499 Kg/CO2e/ML/yr

0 580 - 699 Kg/CO2e/ML/yr

1 450 - 579 Kg/CO2e/ML/yr

2 200 - 449 Kg/CO2e/ML/yr

3 0 - 199 Kg/CO2e/ML/yr

4 -10,000 - -1 Kg/CO2e/ML/yr

5 -22,000 – 10,001 Kg/CO2e/ML/yr

5.2.4. Impact upon environmental flow objectives (river health)

Contribution to meeting environmental flow objectives is used a qualitative assessment (based on

specialist advice) of the impact of each option on river health. In assessing the scores for River

Health, the first step involved determining the relative importance of flow to the health of the river,

and the current health of the river (or catchment). Once this was established, the impact of each

option is scored (according to CRSWS ratings), taking into account the volume and the timing of

extractions or additions, and how these influenced the different components of the flow (e.g. base

flow, bank full, over bank, flushes and flood events).For some options, detailed flow and water

resource studies are currently underway and new information could influence the scoring, which is

identical to that used in the CRSWS.

Score Descriptor

-5 Extreme decline in River Health from reduced flows.

-4 Significant decline in River Health from reduced flows.

-3 Moderate decline in River Health from reduced flows.

-2 Small decline in River Health from reduced flows.

-1 Marginal decline in River Health from reduced flows.

0 No change in flows and River Health from current condition.

1 Marginal improvement in River Health from improved flows.

2 Small improvement in River Health from improved flows.

3 Moderate improvement in River Health from improved flows.

4 Significant improvement in River Health from improved flows.

5 Extreme improvement in River Health from improved flows.

5.2.5. Surface, ground and marine water quality

For surface, ground and marine water quality, each option was assessed on the anticipated impact

on the existing beneficial uses of the water resource affected. Where possible, existing data was

used to inform the qualitative assessment, but in general this criterion has relied on specialist,

general advice. Where appropriate, it also takes into account consideration of the impact of the

released water from some of the options on the receiving environment and potential for leakage

into groundwater from new irrigated agriculture. Scoring is identical to that described in the

CRSWS.

Score Descriptor

-5 Extreme decline in water quality with inability to meet existing beneficial uses all of the time.

-4 Significant decline in water quality with inability to meet existing beneficial uses for most of the time.

-3 Moderate decline in water quality with inability to meet existing beneficial uses some of the time.

-2 Small decline in water quality with inability to meet existing beneficial uses for limited periods.

-1 Marginal decline in water quality but continues to meet existing beneficial uses all of the time.

0 No change in water quality and beneficial uses from current conditions.

1 Marginal improvement in water quality for the existing beneficial uses all of the time.

2 Small improvement in water quality with ability to meet additional beneficial uses for limited periods.

3 Moderate improvement in water quality with ability to meet additional beneficial uses some of the time.

4 Significant improvement in water quality with ability to meet additional beneficial uses most of the time.

5 Extreme improvement in water quality with ability to meet additional beneficial uses all of the time.

5.2.6. Effect on terrestrial ecosystems

The impacts to terrestrial ecosystems have been assessed using a broad level qualitative approach

based on general issues associated with each option and mapping using GIS datasets provided by

South Gippsland Water and DSE. Ecological Vegetation Classes (EVCs) distinguish vegetation

types on the basis of floristic communities, bio-geographic range and habitat requirements. This is

a qualitative assessment that does not profess to take into account the precise location of

infrastructure options (such as options involving significant pipelines).

Score Descriptor

-5 Extreme decline in ecosystem condition as represented by loss of significant EVCs

-4 Significant decline in ecosystem condition as represented by loss of significant EVCs

-3 Moderate decline in ecosystem condition as represented by loss of significant EVCs

-2 Small decline in ecosystem condition as represented by loss of significant EVCs

-1 Marginal decline in ecosystem condition as represented by loss of significant EVCs

0 No change from current conditions

1 Marginal improvement in ecosystem condition as represented by gain of significant EVCs

2 Small improvement in ecosystem condition as represented by gain of significant EVCs

3 Moderate improvement in ecosystem condition as represented by gain of significant EVCs

4 Significant improvement in ecosystem condition as represented by gain of significant EVCs

5 Extreme improvement in ecosystem condition as represented by gain of significant EVCs

5.2.7. Recreation and heritage

The extent of support or opposition to the option as described has been estimated by considering

likely changes in recreational use, aboriginal heritage and other cultural heritage.

Score Descriptor

-5 Extreme decline in cultural, heritage or recreational value

-4 Significant decline in cultural, heritage or recreational value

-3 Moderate decline in cultural, heritage or recreational value

-2 Small decline in cultural, heritage or recreational value

-1 Marginal decline in cultural, heritage or recreational value

0 No change from current conditions

1 Marginal improvement decline in cultural, heritage or recreational value

2 Small improvement decline in cultural, heritage or recreational value

3 Moderate improvement decline in cultural, heritage or recreational value

4 Significant improvement decline in cultural, heritage or recreational value

5 Extreme improvement in cultural, heritage or recreational value

5.2.8. Acceptability

The extent of support or opposition to the option as described has been estimated based on our

understanding of the community. These will be further tested as the various options are presented

to the community.

Score Descriptor

-5 Extreme opposition by the community

-4 Significant opposition by the community

-3 Moderate opposition by the community

-2 Small opposition by the community

-1 Marginal opposition by the community

0 Option is neither supported nor opposed by the community

1 Marginal support across the community

2 Small support across the community

3 Moderate support across the community

4 Significant support across the community

5 Extreme support across the community

5.2.9. Confidence of Success

Confidence is a measure of the extent of evidence base and reflects the inherent uncertainty in a

preliminary assessment. Confidence will vary according to the extent of information available to

support the particular option.

Score Descriptor

1 Low confidence: Lack of understanding of risks that may impact on volumes being realised over the long term. Limited evidence in support.

2 Medium confidence: Reasonable understanding of risks that may impact on volumes being realised over the long term. Reasonable evidence in support.

3 High confidence: Wide agreement, multiple findings supported by research, high degree of consensus, considerable evidence. Considerable evidence in support.

5.2.10. Fairness

The fairness flag used in the Central Region Sustainable Water Strategy TBL assessment has not

been adopted by South Gippsland Water. The concept of fairness has been incorporated into the

social acceptability score.

6. Overall Approach to Assessing Demand Reduction and Supply Enhancement Options

The previous sections of this document present background information on the long-term planning

objectives (Section 2), the regulatory framework within which the supply systems are managed and

planned for (Section 3), current and projected demands over the 50 year planning horizon (Section

4), and a description of the assessment method used to compare the sustainability of alternative

demand reduction and supply enhancement options (Section 5). The following sections of this

document present, for each supply system:

the supply and demand projections for each supply system over the planning horizon;

whether level of service objectives are currently being met and whether they will continue to

be met over the 50 year planning horizon with current operation and infrastructure; and

actions proposed by South Gippsland Water to reduce demand and/or increase supply to

continue to meet level of service objectives over the 50 year planning horizon, if required.

For a number of supply systems, current water availability is sufficient to meet projected demands

over the next 50 years and no further actions are required, other than to continue demand

management activities in line with other supply systems and to continue to manage operations

efficiently and effectively.

For the supply systems where level of service objectives are unlikely to be met over the planning

horizon with current operation and infrastructure, a range of options have been considered.

Options that were previously considered to be infeasible or not cost-effective in past long-term

planning strategies by South Gippsland Water have not been revisited in detail in this current

document.

The towns of Poowong, Loch, Nyora, Korumburra, Leongatha and Koonwarra are referred to

collectively as South Gippsland Water‟s “northern towns”, whilst Wonthaggi, Cape Paterson and

Inverloch are referred to as South Gippsland Water‟s “southern towns”. For these northern and

southern towns and nearby unserviced towns, there is the possibility of an interconnected supply

system partly supplied from the Melbourne system. Given the possibility of this supply system

integration, the supply and demand projections for each individual supply system are presented first

under current operation and infrastructure arrangements in Sections 7-11. A collective strategy for

these northern and southern towns is then presented in Section 12 under two broad approaches,

namely with or without a connection to the Melbourne supply.

For the central towns, there is the potential to collectively supply Toora, Foster, Fish Creek and

nearby unserviced towns. For these towns the supply and demand projections for each individual

system are presented first under current operation and infrastructure arrangements in Sections 13-

18. A collective strategy for these towns is then presented in Section 19 under two broad

approaches, namely for standalone systems (without supply to nearby unserviced towns) and a

linked system (with supply to nearby unserviced towns). A potential connection of the Melbourne

supply system to these towns was briefly considered but dismissed due to high costs and was not

investigated further. The supply systems for Meeniyan and Dumbalk, which may be merged to

minimise water treatment costs, are only considered as standalone systems in the WSDS as any

decision to merge these two systems is not driven by consideration of water resource availability.

For the eastern towns of Yarram, Port Albert, Alberton and Devon North, which form the Tarra

River supply system, the supply and demand projections under current operation and infrastructure

are presented alongside the demand reduction and supply enhancement options in Section 20.

7. Supply and Demand Projections for Poowong, Loch and Nyora with Current Operation and Infrastructure

7.1. Introduction

This section of the WSDS outlines the supply and demand projections for Poowong, Loch and

Nyora over the next 50 years assuming current operation and infrastructure. It includes an

overview of the current supply system configuration, current demand for water and current supply.

It also includes supply and demand projections under future climate change and alternative growth

scenarios over the 50 year planning horizon. South Gippsland Water‟s response to any shortfall in

demand under the current operation and infrastructure scenarios is presented in Section 12 in

conjunction with nearby towns.

7.2. Current water supply and demand

7.2.1. Supply system description

The Little Bass River supply system services the townships of Poowong, Loch and Nyora. A

schematic representation of this system is shown in Figure 7-1. The system is supplied from the

Little Bass Reservoir on the Little Bass River, approximately 2.5 km south-east of Poowong. The

storage has a capacity of 202 ML. A pump operates at approx. 17 L/s (1.5 ML/d), with a maximum

capacity of 22 L/s (1.9 ML/d) at the Little Bass Reservoir to pump water up the hill to the treatment

plant.

Figure 7-1 Little Bass Water Supply System Schematic

7.2.2. Current legal entitlements to water

The bulk entitlement for Poowong, Loch and Nyora allows South Gippsland Water to divert up to a

maximum of 420 ML/yr from the Little Bass River at the Little Bass Reservoir. The daily bulk

entitlement is shown in Table 7-1.

Table 7-1 Bulk entitlement volume for the Little Bass River

Source Maximum

annual volume

(ML/yr)

Maximum

diversion rate

(ML/d)


Little Bass River 420 2.7 Minimum of 0.5 ML/d or natural flow

South Gippsland Water also has a bulk entitlement to access up to 1,000 ML/yr from the

Melbourne system to potentially supply Korumburra, Poowong Loch and Nyora when the

desalination plant at Wonthaggi and Melbourne supply pipeline has been commissioned. A

physical connection between Korumburra and the Melbourne supply system does not currently

exist, so this supply source could only be accessed if South Gippsland Water decides to connect

Korumburra to the Melbourne supply.

Little Bass Reservoir

Little Bass

River

treatment plant

service basinNYORA

STORAGES:

Little Bass Reservoir - earthen, open, 196 ML

Service basin - concrete, lined & covered, 2 ML

Poowong water tower - concrete, roofed, 200 kL

Loch water tower - concrete, roofed 180 kL

Nyora water tower - concrete, roofed, 180 kL

POOWONG

pump station

LOCH

water tower

chloramine

water tower

water towerpump station

Little Bass Water Supply System

aeration

powdered

activated carbon

ESTIMATED POPULATION:

Poowong 360

Loch 220

Nyora 400

Towns are not sewered.

SOURCE: Littel Bass River

TREATMENT: Full treatment of alum, soda ash, potassium

permanganate, sodium hypochlorite, amonia coagulation,

filtration, chloramination. Aeration at Little Bass Reservoir

and powdered activated carbon dosing.

Area Supervisor

Date Issued

Revision No.

SOUTH GIPPSLAND WATERManager

02/07/2004

1.0

Not yet

Brian Ashworth

202 ML

7.2.3. Current demand

Poowong, Loch and Nyora had populations of 265, 172 and 539 respectively in the 2006 census

excluding visitors (DPCD, 2009). This corresponds to a total of 976 people for the three towns. A

demand model was fitted to the recent unrestricted data to estimate a long-term average annual

demand, which takes into account how current demands would vary under a wider range of natural

climate variability. The historical and estimated long-term current demand is shown in Figure 7-2.

The estimated long-term current demand is 264 ML/yr at South Gippsland Water‟s treatment plant

inlet, of which around 9% is utilised on average through the treatment plant. The variation in

estimated demands throughout the year is shown in Figure 7-2, which shows that there is a

relatively high base demand and that there is not a clear seasonal pattern of demand. This is

believed to be due to the variable water use associated with the major customer of the Poowong

Abattoir.

Figure 7-2 Long-term current monthly demands for Poowong, Loch and Nyora

7.2.4. Current Reliability of Supply

Over the last decade, restrictions at Poowong, Loch and Nyora were put in place in 2003 and 2007.

Since these restrictions were implemented, the level of demand has reduced and there has been a

slight increase in the estimated available storage capacity in Little Bass Reservoir. Reliability of

supply modelling over the period July 1950 to June 2007 indicated that restrictions at the current

0

5

10

15

20

25

30

35

Jul-01 Jul-02 Jul-03 Jul-04 Jul-05 Jul-06 Jul-07 Jul-08 Jul-09 Jul-10

De

man

d F

rom

Tre

atm

en

t P

lan

t (M

L/m

th)

Historic

Estimated

Restrictions

level of demand would be required much less frequently than has occurred over the last decade,

with restrictions being required once every 19 years on average (i.e. 95% annual reliability). This

meets South Gippsland Water‟s level of service objectives to not restrict supply more frequently

than 1 year in 10. The estimate of current reliability of the supply system has increased since the

previous WSDS estimate in South Gippsland Water (2007) for the reasons noted above. Further

details on the water resource model used to assess reliability of supply (and yield) can be found in

SKM (2009).

7.3. Environmental condition

Little Bass River is a tributary of the Bass River and flows into the Bass River south of Poowong.

At Poowong the Little Bass River flows through steep and undulating cleared farmland, increases

in width to about 4m downstream of Poowong with pools up to 110cm deep and riffles to 20cm

deep (DPI, 2007). The river is in a stable condition with good riparian vegetation. The Little Bass

River has rubble, gravel and sand substrate with areas of debris and excellent fish habitat (DPI,

2007). The river contains some brown trout (Salmo trutta) and short-finned eels (Anguilla

australis) and also possibly other species that also occur in the Bass River. There are no Index of

Stream Condition (ISC) sites on the Little Bass River and other information about the stream is

limited.

It is difficult to assess the impact of changes in flow on the condition of the Little Bass River as

detailed data on the flora and fauna is limited. However, the main risks would be from actions that

reduced summer flows. Reduced summer flows could result in shallower pools with degraded

water quality and reduced available habitat for fish and other aquatic fauna. In addition riffles may

dry up reducing connectivity between pools along the river.

Lloyd Environmental et al. (2008) provided flow recommendations for the Little Bass River. The

study reported that short periods of cease to flow provide conditions suitable for germination and

growth of the herbs and sedges which run between natural pools. Summer low flows are required

to maintain perennial habitat for semi-emergent aquatic vegetation, fringing emergent vegetation,

fish and macroinvertebrate communities. A spring-summer recession flow was recommended to

ensure successful recruitment of flat-headed gudgeon, river blackfish and to facilitate the parallel

expansion of the macroinvertebrate population. Two low flow freshes per year were considered to

allow local fish passage as well as supporting a range of other objectives, whilst less frequent low

flow freshes of a higher volume were associated with short-finned eel migrations. Winter

baseflows were associated with maintaining aquatic plants, whilst high flow freshes contributed to

maintaining shrubland vegetation and promoting fish spawning. Bankfull flows were important for

maintaining sediment transport to downstream reaches, whilst overbank flows at this location were

not linked to any particular ecological objective and were considered insufficient to dislodge the

build up of macrophytes in this reach.

7.4. Water supply and demand projections with current operation and infrastructure

7.4.1. Historical trends

Historical demands at Poowong, Loch and Nyora have been steadily increasing since the mid

1990s, with the exception of the last two years, when demands have decreased markedly, as can be

seen in Figure 7-3. These demands are recorded at the clear water storage outlet and do not include

an allowance for treatment plant utilisation. The number of customers billed in this supply system

has been steadily increasing over the last five years. This potentially indicates that significant

water savings have been achieved by South Gippsland Water and its customers in recent years,

however it should be noted that annual major industrial water use dropped by around 40 ML in the

three years since 2006/07, which would account for much of the recent decline.

Figure 7-3 Historical demands and number of customers billed at Poowong, Loch and Nyora

The population of Nyora has grown steadily over the last two decades, with population of the other

two towns remaining relatively constant. The total population for all three towns increased from

671 people in 1981 to 971 people in 2006, as shown in Figure 7-4. Between 2001 and 2006

however there was a slight decline in population, due to a decline in population at Poowong and

Loch and only a modest increase in population at Nyora. The number of dwellings increased at

each individual town over the years 2001 to 2006.

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Demand

No. of customers billed

Years af fected by restrictions

Figure 7-4 Historical population in Poowong, Loch and Nyora

7.5. Future demand projections

Two estimates of future growth in water demand were made in the previous strategy (South

Gippsland Water, 2007). These included the Victoria in Future estimates, which are available at a

Statistical Local Area (SLA) level, and a Local Growth scenario which considered the potential for

stronger growth within towns at a rate greater than the surrounding SLA. There are five SLA‟s

covering South Gippsland Water‟s water supply area. Poowong, Loch and Nyora are located

within the South Gippsland Shire West SLA and account for around 12% of the population within

the SLA.

A comparison of the 2006 census results for each town against the previous population projections

from the 2001 census indicated that both the Victoria in Future and the Local Growth scenario

overestimated population growth between 2001 and 2006. The Victoria in Future projections were

closer to the growth which actually happened, which was a fall in population of 5% for the supply

system. Given the uncertainty of future population, South Gippsland Water has considered two

population forecasts, which include the Victoria in Future projections and a higher Local Growth

scenario that allows for faster growth in urban centres within SLAs.

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Victoria in Future projections include a growth in residential demand of between 0.6% to 1.1% per

year and no change in major industrial demand. The Local Growth scenario assumes a 1.5%

annual growth rate in residential demand up to the year 2015, then a 2.5% growth in demand to the

year 2039 and a 1.5% growth rate thereafter. An allowance for an increase in major industrial

demand from the current 89 ML to a future 230 ML by the end of the planning horizon has also

been made in this Local Growth scenario.

An additional 2.5% increase in residential and stock and domestic demand was assumed to occur

over the next 50 years due to medium climate change for all population forecasts. This additional

increase in demand is due to increased water use activities such as garden watering under drier and

hotter climate change conditions and is consistent with DSE recommendations (DSE, 2005).

7.5.1. Future supply projections with current operation and infrastructure

Under the medium climate change scenario, runoff in the South Gippsland Basin in the year 2058

relative to the year 2009 is estimated to decrease by 15%, with a range of reduction of 7% to 28%

under low and high climate change scenarios. Under the medium climate change scenario, this

change in streamflow would be driven by a 3% reduction in rainfall and a 7% increase in

evaporation. Under the ongoing low flow conditions scenario, Little Bass River streamflows

upstream of Little Bass Reservoir have been reduced by 41% prior to July 1997.

The Current Operation and Infrastructure water supply and demand situation for the Little Bass

supply system using the Victoria in Future population projection is shown in Figure 7-5. This

figure illustrates that if no further action is taken and growth in demand for water occurs in

accordance with Victoria in Future population projections, demand would exceed available supply

at South Gippsland Water‟s level of service objective in the next year or two. For the higher Local

Growth scenario, which is also shown in Figure 7-5, the shortfall in supply by the end of the 50

year planning horizon is significantly higher than the Victoria in Future growth scenario.

Figure 7-5 Water Supply and Demand for Poowong, Loch and Nyora with current operation and infrastructure

7.6. Sensitivity of projections

Three potential land use changes within the catchments supplying Poowong, Loch and Nyora were

investigated to understand the potential risk they could pose to available supply.

Bushfires: Only 8% of the Little Bass River catchment has vegetation cover. This means that the

risk of catchment yield decreasing significantly due to the effects of bushfires is low. There is no

record of bushfires occurring in the catchment over the last few decades.

Logging: No logging is undertaken under regional forestry agreements in the water supply

catchment for this supply system.

Plantations: There are no plantations in the water supply catchment for this supply system.

Further comments on the sensitivity of the demand projections to demand uncertainty are also

presented.

Future development: It is speculated that future residential development at the growth rates

adopted in the Local Growth scenario may occur because the towns are within commuting distance

to parts of Melbourne and because reticulated sewerage will be provided. An examination of the

planning scheme for Nyora indicated that any future large scale lot development at Nyora would

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Victoria In Future demand under medium climate change

Local growth demand under medium climate change

Yield under medium climate change

Yield under ongoing low flow conditions

require an amendment to the planning scheme, which is typically a 1-2 year process. A discussion

of the limited potential for future growth within the current planning scheme is presented in

Appendix C.

Areas along the South Gippsland Highway closer to Melbourne have grown at a faster rate than

Nyora in recent years and indicate the potential for growth at Nyora in the future. From 2001 to

2006, the City of Casey – Cranbourne Statistical Local Area (SLA) population increased by 28%,

whilst the Shire of Cardinia – South SLA population, which includes Koo Wee Rup, increased by

7%. This is in contrast to Nyora, which did not grow in population over the 2001 to 2006 period.

The Local Growth scenario takes the potential for higher population growth at Poowong, Loch and

Nyora into account.

7.7. Additional demand reduction options

If the additional demand reduction options outlined in Section 4.10 are adopted for Poowong, Loch

and Nyora, demands in the future would still remain above the available supply at South Gippsland

Water‟s level of service objectives, as shown in Figure 7-6, however the magnitude of future

supply augmentations would not need to be quite as high.

Figure 7-6 Effect of additional demand reduction options for Poowong, Loch and Nyora

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Local growth demand under medium climate change with future demand reduction measures



7.8. Summary of the supply and demand for Poowong, Loch and Nyora with current operation and infrastructure

In summary for Poowong, Loch and Nyora under the Current Operation and Infrastructure supply

and demand scenarios:

Existing supply is just sufficient to meet South Gippsland Water‟s current level of service

objectives under medium climate change and is just below those service objectives under a

continuation of the ongoing low flow conditions that have occurred since July 1997;

Demand for water over the next few years is expected to exceed available supply at South

Gippsland Water‟s level of service objectives due to population growth and growth in

industrial demand for water, potentially creating a significant shortfall in supply in 50 years

time;

Demand for water has fallen in recent years, as has population, but the number of dwellings

has increased; and

Demand reduction initiatives will reduce the magnitude of any future supply enhancement, but

some form of supply enhancement will still be required over the 50 year planning horizon.

South Gippsland Water‟s strategy to address this future supply shortfall is presented in Section 12.

8. Supply and Demand Projections for Korumburra with Current Operation and Infrastructure

8.1. Introduction

This section of the WSDS outlines the supply and demand projections for Korumburra over the

next 50 years assuming current operation and infrastructure. It includes an overview of the current

supply system configuration, current demand for water and current supply. It also includes supply

and demand projections under future climate change and alternative growth scenarios over the 50

year planning horizon. South Gippsland Water‟s response to any shortfall in demand under the

current operation and infrastructure scenarios is presented in Section 12 in conjunction with nearby

towns.



Supply to Korumburra is from three service reservoirs located on three separate tributaries to the

north of the township. The total live system storage capacity is 658 ML, with no assumed dead

storage. The town‟s water supply is drawn from the No. 1 Reservoir on Coalition Creek which has

a current capacity of 222 ML. The outlet capacity from the No. 1 storage is 4.5 ML/day and water

from the No. 2 Reservoir (Ness Creek - total capacity 74 ML) is pumped into the No. 1 Reservoir

to top up the storage between mid-spring and mid-summer. The capacity for water transfer from the

No. 2 storage to the No. 1 storage is 10 L/s. When the live volume in No. 1 storage drops below

160 ML, water is pumped from the No. 3 Reservoir (Bellview Creek, total capacity 362 ML) into

the No. 1 storage. The outlet capacity from the No. 3 storage is 2 ML/d. If necessary, water can be

pumped directly from the No. 3 Reservoir to the treatment plant. A schematic representation of the

system is presented in Figure 8-1.

Figure 8-1 Coalition Creek Water Supply System Schematic


The bulk entitlement for Korumburra allows South Gippsland Water to divert up to a maximum of

1000 ML/yr from Coalition, Ness and Bellview Creeks, and up to 1,800 ML/yr from the Tarwin

River West Branch. Daily bulk entitlements are shown in Table 8-1.

Korumburra Water Supply System Area Supervisor

Date Issued

Revision No.


02/07/2004

1.0

Not yet

Brian Ashworth

PAC

POPULATION: Estimated 3,400 - Town is sewered.

TREATMENT: Full treatment with PAC, alum, potassium permanganate, soda

ash, chlorine (gas), coagulation, sedimentation, filtration, chlorination Aeration

at No. 1 & 3 reservoirs (PAC - powdered activated carbon - only used 1or 2

weeks per year)

pump

pump

Coalition Creek Reservoir

(all year use)

Bellview Creek Reservoir

treatment

plant

chlorine

gas

KORUMBURRA

clear water

storage

STORAGES:

Ness Gully Reservoir (No. 2 Res) - earthen, open, 74 ML

Coalition Creek Reservoir (No. 1 Res) - earthen, open, 169 ML

Bellview Creek Reservoir (No. 3 Res) - earthen, open, 342 ML

Clear Water Storage Tank - concrete, roofed, 4.5 ML

2 Water Towers - steel, roofed, 317 kL each

SOURCE: Coalition Creek, Bellview Creek, Ness Creek

pump station

Ness Gully Reservoir

pump

station

Airlie Park

water tower

Mine Rd

water tower

pump station

cap 8 ML/d

cap 2 ML/d

cap 4.5 ML/d

aeration

362 ML

222 ML

Table 8-1 Daily Bulk Water Entitlement and equivalent monthly volumes for Korumburra

Source Maximum

annual

volume

(ML/yr)

Max diversion

rate (ML/d)

Max diversion

rate (ML/mth)


Coalition Creek 1000 4.8 145.9 Minimum of 0.6 ML/d

(18.24 ML/mth) or natural flow

Ness Creek 1.6 (Oct-Dec)

0.0 (Jan-Sep)

48.6 (Oct-Dec)

0.0 (Jan-Sep)

Minimum of 0.6 ML/d


Bellview Creek 3.0 91.2 Minimum of 1.0 ML/d


Tarwin River West

Branch at Koonwarra(1)

1800(2)

10.0 (May-Nov)

5.0 (Dec-Apr)(3)

304.0 (May-Nov)

152.0 (Dec-Apr)



(1) This supply to Korumburra is currently complex and difficult to operate and only suitable for use in severe drought.

(2) Less any water diverted under the Leongatha bulk entitlement from the Tarwin River West Branch or lower Coalition

Creek. In a drought year this diversion to Leongatha is estimated to be in the order of 1200-1300 ML/yr

(3) Summer diversion only available until 30 June 2015 as an interim measure

During the 2006/07 water year, temporary pumping occurred from the Tarwin River West Branch

to Korumburra and Leongatha. This was formalised into a qualification of rights to the Meeniyan

bulk entitlement on 13 June 2008 prior to being incorporated into an amendment to the

Korumburra and Leongatha bulk entitlements on 19 October 2010. The Current Operation and

Infrastructure scenario for the WSDS assumes that pumping from the Tarwin River West Branch to

Korumburra and Leongatha occurs in accordance with the amended bulk entitlement, but at the

current diversion infrastructure capacities, which are lower than those allowable in the bulk

entitlement amendment. Further detail on the assumed operation of the diversion from these

sources is shown in Table 8-2, which assumes current diversion infrastructure capacities. It should

be noted that the supply from the Tarwin River West Branch to Korumburra utilises existing

obsolete infrastructure that is complex and difficult to operate. Hence this source of supply to

Korumburra is currently only suitable for use in a severe drought.

Full use of the amended entitlement by upgrading diversion infrastructure capacities is discussed as

a supply enhancement option later in this document (Section 12.2.2).

Table 8-2 Tarwin River West Branch Diversion Rules for Current Operation and Infrastructure Scenario

Pumping Rule

Tarwin River at Koonwarra

(pumping to Ruby Creek Storages and Ness Gully

Storage)

Coalition Creek at pump site (pumping to Ruby Creek

Storages)

Minimum passing flow (ML/day)

100 10

Extraction volume (ML) 1800 minus Coalition Ck volume 800

Extraction period May-Nov May-Nov

Upper limit on pumping capacity (ML/day)

5 minus Coalition Ck rate 5

Capacity Sharing (Ruby Ck No 4 : Ness Gully No. 2)

3 ML/day maximum to Leongatha, 3 ML/day maximum to

Korumburra(1)

To Ruby Creek Storages(2)

Pipe capacities 5 ML/d at extraction point. 3ML/d to Ness Gully, 3ML/d to Ruby Ck

storages

5 ML/d


(2) Modelling assumes supply to No.4 reservoir. Current connection only extends to No. 3 reservoir, but temporary

pumping arrangements could transfer up to No. 4 reservoir if required in practice.

The amendment to the Korumburra bulk entitlement in October 2010 also allows South Gippsland

Water to increase storage capacity by 200 ML. This supply enhancement option is discussed later

in this document (Section 12.2.2).

There are several groundwater bores in the Korumburra and Leongatha areas. The Current

Operation and Infrastructure scenario in the WSDS assumes that groundwater pumping occurs as

per the rules outlined in Table 8-3. These rules incorporate the licence conditions on the

groundwater licence issued by Southern Rural Water in 2010, but conservatively assume that only

1.0 ML/d can be sustained from the bores rather than the 2.1 ML/d that has been licensed.

Additional pumping above 1.0 ML/d may occur as an emergency supply measure in extreme

drought.

Table 8-3 Groundwater Pumping Rules for Current Operation and Infrastructure Scenario

Pumping Rule Bores supplying Leongatha only Bores supplying both Leongatha

and Korumburra(1)

Bores S9025900/2, 138891 and S9026806/1

S9029805/2

Total extraction rate (ML/d) 0.5 0.5

Relevant storages that trigger pumping

Ruby Creek All storages in Leongatha and Korumburra system

Bore pumping triggers During the period Oct-Dec: relevant storages at 75% of capacity triggers pumping to start and stop

During the period March-May: relevant storages <50% of capacity triggers pumping to start, and 75% of capacity triggers pumping to stop



Melbourne system to potentially supply Korumburra, Poowong Loch and Nyora when the

desalination plant at Wonthaggi and Melbourne supply pipeline has been commissioned. A

physical connection between Korumburra and the Melbourne supply does not currently exist, so

this supply source could only be accessed if South Gippsland Water decides to connect

Korumburra to the Melbourne supply.


Korumburra had a population of 2,974 people excluding visitors in the 2006 census (DPCD, 2009).

Historical demand over the last three years has ranged from 530-640 ML/yr. Demand data prior to

this was restricted. A demand model was fitted to the recent unrestricted data to estimate a long-

term average annual demand, which takes into account how current demands would vary under a

wider range of natural climate variability. The historical and estimated long-term current demand

is shown in Figure 8-2. The estimated long-term current demand is 621 ML/yr at South Gippsland

Water‟s treatment plant inlet, of which around 3% is utilised on average through the treatment

plant. The variation in demands throughout the year is also shown in Figure 8-2, which shows that

demand varies seasonally with climate, but that base demand in winter is relatively high.

Figure 8-2 Long-term current monthly demands for Korumburra

8.2.4. Current reliability of supply

Since the mid-1990s, restrictions have occurred in Korumburra in 2000/01, 2002/03, 2005/06

through to early 2007/08. Stage 4 (of 4 stages) restrictions were implemented in 2006/07. Since

2006/07 the supply and demand balance has been improved through a reduction in demand and the

development of revised restriction triggers. Reliability of supply modelling over the period July

1950 to June 2007 indicated that restrictions would only have been required once over the last 57

years under a repeat of historical climate conditions, which meets South Gippsland Water‟s level of

service objective for restrictions. The minimum storage volume reached under this scenario was

estimated to be 165 ML. Further details on the water resource model used to assess reliability of

supply (and yield) can be found in SKM (2009).


Three creeks form the primary supply to Korumburra, namely Coalition Creek, Ness Creek and

Bellview Creek. Coalition Creek is a tributary of the Tarwin River West Branch and is joined by

Ruby Creek (supplying Leongatha) just before its confluence with the Tarwin River West Branch.

Information about the environmental condition of Coalition Creek was assessed for South

Gippsland Water in SKM (2006a) Coalition Creek Preliminarily Environment Assessment. The

key outcomes of that assessment of relevance to the WSDS are:

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The creek flows through a predominantly rural setting through land that has been cleared for

dairy farming.

Many sections of the creek are infested with willows and other weeds, however some willow

removal has occurred and revegetation at these sites is now starting to provide shade to the

creek.

Willow removal and subsequent revegetation is planned for a number of locations along the

creek, which will require available water to assist in maintaining seedlings during the summer

months.

Pockets of remnant native vegetation require streamflows to be maintained to ensure

maintenance of existing mature trees and to promote establishment of seedlings.

The creek ceases to flow in summer, but in some areas there are permanent water pools which

are an important summer refuge for aquatic fauna. Any premature drying of the pools due to

changes in summer flow regime could impact on ability of small bodied fish to avoid larger

predatory species.

Water quality in the creek is generally poor and the benefit of permanent water pools for

summer refuge may be reduced by poor water quality.

In a previous fish survey, no native fish species were found in the creek. Access to Coalition

Creek by many of the native migratory fish in the Tarwin River catchment would be limited by

flow regime and existing fish barriers.

Ness Creek is a major tributary of Coalition Creek and the health of Coalition Creek largely reflects

the health of Ness Creek. There are no Index of Stream Condition sites or water quality data on

Ness Creek and available information is limited. It is difficult to assess the impact of changes in

flow on the condition of Ness Creek, however the main risks to the aquatic fauna and flora are

probably degradation of water quality, reduction of available habitat for aquatic fauna, and impacts

that may affect the riparian vegetation.

The above assessment was confirmed in the environmental flow assessment for Coalition Creek in

SKM (2009). The environmental flow assessment linked the provision of low flows to maintaining

connectivity between pools, maintaining water quality in pools and to provide moisture for riparian

and fringing plants. Summer freshes were important for preventing colonization of riparian areas

by terrestrial plants, to entrain organic matter and transport nutrients downstream. Winter low

flows were designed to maintain habitat and prevent colonisation of weeds, while high flow freshes

were intended to maintain channel forming processes and to facilitate the upstream migration of

Tupong and juvenile fish species. Bankfull flows were recommended to maintain channel forming

processes and no overbank flows were specifically recommended.

Bellview Creek is a tributary of the Bass River. The conditions in the Little Bass River previously

presented in the environmental description of that river for the Poowong, Loch and Nyora supply

would be similar to Bellview Creek.

Information about the environmental condition of Tarwin River West Branch and the Tarwin River

downstream of the confluence of the East and West Branches was assessed for South Gippsland

Water in SKM (2006b) Tarwin River Preliminarily Environment Assessment. The main relevant

outcomes of that assessment are discussed below.

Around 30 fish species have been recorded in the Tarwin River downstream of its confluence with

the West Branch. One fish species (Australian grayling, Prototroctes maraena) recorded in the

study area is listed nationally as vulnerable under the Environment Protection Biodiversity

Conservation Act 1999 (National) and as threatened in Victoria under the Flora and Fauna

Guarantee Act 1988 and one species (Australia whitebait, Hyperlophus vittatus) is listed as

threatened in Victoria under the FFG Act 1988. The list of species found also included the two

exotic species of carp and brown trout.

Recent work by the Department of Sustainability and Environment (DSE) has recorded substantial

populations of Australian grayling in the Tarwin River immediately below the weir at Meeniyan.

Consequently, both branches of the Tarwin River have been identified as having significance for

populations of Australian grayling (Justin O‟Connor, pers. com. DSE, Freshwater Ecology).

Australian grayling spawn from about April through to July. At the time of spawning the juveniles

move downstream and then move back upstream in October to November. It is believed Australian

grayling need an increase in river flow to induce spawning (Justin O‟Connor, pers. com.).

Installation of a fish ladder at the weir at Meeniyan was identified as a priority by DSE (Justin

O‟Connor, pers. comm.) and has now been installed.

Water quality was found to be poor at the site on the West Branch of the Tarwin River near

Koonwarra and was above the State Environment Protection Policy guideline values.

The above assessment was confirmed in the environmental flow assessment for the Tarwin River

West Branch in SKM (2009). The environmental flow assessment linked the provision of low

flows to maintaining habitat in pools for river blackfish, to maintain habitat, to allow fish

movement, and to provide moisture for riparian and fringing plants. Summer freshes were

important for preventing colonization of riparian areas by terrestrial plants, to entrain organic

matter and transport nutrients downstream, whilst slightly higher, short duration transitional flows

in summer were considered important for triggering fish migration. Winter low flows were

designed to maintain habitat, inundate paperbarks and prevent colonisation of weeds, while high

flow freshes were intended to maintain channel forming processes and to facilitate the upstream

migration of Tupong and juvenile fish species, including Australian Grayling and Galaxiids.

Bankfull flows were recommended to maintain channel forming processes and no overbank flows

were specifically recommended.



Historical demand at Korumburra decreased significantly from 2004/05 and in 2009/10 was around

40% lower than the peak annual demand in 2004/05, as shown in Figure 8-3. These demands are

recorded at the clear water storage outlet and do not include an allowance for treatment plant

utilisation. The number of customers billed has increased slightly despite the reduction in demand.

This potentially indicates that significant water savings have been achieved by South Gippsland

Water and its customers in recent years. Major industrial demand for water at Korumburra since

2006/07 has remained relatively constant and accounts for only a small portion of the observed

variability in demand over the last few years.

Figure 8-3 Historical demand and number of customers billed at Korumburra

The population of Korumburra has remained relatively static over the last few decades, as shown in

Figure 8-4, with the population increasing only marginally from 2,954 in 1991 to 2,974 in 2006.

The number of dwellings has however increased consistently in every census since 1981.

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Figure 8-4 Historical population in Korumburra

8.4.2. Future demand projections





covering South Gippsland Water‟s water supply area. Korumburra is located within the South

Gippsland Shire West SLA and accounts for around 37% of the population within the SLA.

A comparison of the 2006 census results for Korumburra against the previous population

projections from the 2001 census indicated that both the Victoria in Future and the Local Growth

scenarios overestimated population growth between 2001 and 2006. The Victoria in Future

projections were closer to the growth which actually happened, which was an increase in

population of 0.2% for the supply system. Given the uncertainty of future population, South

Gippsland Water has considered two population forecasts, which include the Victoria in Future

projections and a higher Local Growth scenario that allows for faster growth in urban centres

within SLAs.

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year and no change in major industrial demand. The Local Growth scenario assumes a 1.5%

annual growth rate in residential demand over the planning horizon. It also assumes a 10%

increase in major industrial demand in the year 2015 and a further 10% increase in the year 2040.



increase in demand is due to increased water use for activities such as garden watering under drier

and hotter climate change conditions and is consistent with DSE recommendations (DSE, 2005).






evaporation. Under the ongoing low flow conditions scenario, total inflows to the Korumburra

storages have been reduced by 39-41% prior to July 1997.

The Current Operation and Infrastructure water supply and demand situation for the Korumburra



accordance with population projections, demand will exceed available supply at South Gippsland

Water‟s level of service objective within the next few years under the medium climate change

scenario. South Gippsland Water‟s level of service objective is not currently being met under the

ongoing low flow conditions scenario. For the higher Local Growth scenario, the shortfall in

supply by the end of the planning horizon is greater than for the Victoria in Future growth scenario,

as shown in Figure 8-5. Note that the Tarwin River West Branch and groundwater supply to

Korumburra are excluded from the yield presented in Figure 8-5, because it is assumed that these

supply sources are only utilised in severe droughts.

Figure 8-5 Water Supply and Demand for Korumburra with Current Operation and Infrastructure

8.5. Sensitivity of supply to catchment land use change

Three potential land use changes within the catchments supplying Korumburra were investigated to

understand the potential risk they could pose to available supply.

Bushfires: Only 12% of the Coalition, Ness and Bellview Creek catchment has vegetation cover.

This means that the risk of catchment yield decreasing significantly due to the effects of bushfires

is low. There is no record of bushfires occurring in the catchment over the last few decades.





If the additional demand reduction options outlined in Section 4.10 are adopted for Korumburra,

demands would still exceed available supply in the short-term, as shown in Figure 8-6. Whilst

these demand reduction options are an action by South Gippsland Water, they will apply equally

across all supply systems and have therefore been included in the discussion of Current Operation

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and Infrastructure supply and demand situation for each supply system. In Korumburra, this

additional demand reduction would serve to reduce the size of any supply augmentation.

Figure 8-6 Effect of additional demand reduction options for Korumburra

8.7. Summary of the supply and demand for Korumburra with current operation and infrastructure

In summary for Korumburra under the Current Operation and Infrastructure supply and demand

scenarios:

Existing supply just meets South Gippsland Water‟s current level of service objectives under

the medium climate change scenario, but does not meet those objectives under the ongoing low

flows scenario;

Demand for water is expected to exceed available supply at South Gippsland Water‟s level of

service objective over the next few years due to population growth and growth in industrial

demand for water, potentially creating a significant shortfall in supply in 50 years time;

Demand for water has fallen in recent years, whilst population has remained static and the

number of dwellings has increased; and



South Gippsland Water‟s strategy to address this future supply shortfall is presented in Section 12.

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9. Supply and Demand Projections for Leongatha and Koonwarra with Current Operation and Infrastructure

9.1. Introduction

This section of the WSDS outlines the supply and demand projections for Leongatha and

Koonwarra over the next 50 years assuming current operation and infrastructure. It includes an

overview of the current supply system configuration, current demand for water and current supply.

It also includes supply and demand projections under future climate change and alternative growth

scenarios over the 50 year planning horizon. South Gippsland Water‟s response to any shortfall in

demand under the current operation and infrastructure scenarios is presented in Section 12 in

conjunction with nearby towns.



Leongatha derives its water supply by gravity from four reservoirs on Ruby Creek. These four

reservoirs have a combined capacity of 1,911 ML with no dead storage. The capacity and

construction history for each storage is shown in Table 9-1. The Ruby Creek system is the only

source of supply for the township of Leongatha/Koonwarra and for several rural properties. It is

also the supply source for the Murray Goulburn Milk factory. Figure 9-1 shows a schematic

representation of the system. During the 2006/07 water year emergency pumping was undertaken

from Coalition Creek and Tarwin River West Branch downstream of Coalition Creek. This

emergency pumping was to aid the supply to Leongatha (South Gippsland Water, 2007).

Table 9-1 Leongatha water supply reservoirs (South Gippsland Water, 2007)

Reservoir Year constructed Capacity (ML)

Reservoir No. 1 1906 19

Reservoir No. 2 1928 84

Reservoir No. 3 (Hyland) 1960 671

Reservoir No. 4 (Western) 1980 1,137

Total 1,911

Figure 9-1 Ruby Creek Water Supply System Schematic


The bulk entitlement for Leongatha allows South Gippsland Water to divert up to a maximum of

2,476 ML/yr from Ruby Creek, and up to 1,800 ML/yr from the Tarwin River West Branch and

lower Coalition Creek. The daily and equivalent monthly bulk entitlement is shown in Table 9-2.

Table 9-2 Bulk entitlement volume for Ruby Creek (South Gippsland Water, 2007)

Source

Maximum

annual

volume

(ML/yr)

Maximum

diversion rate

(ML/d)


Ruby Creek 2,476 17.3 Minimum of 0.5 ML/d (15 ML/mth) or

natural flow

Coalition Creek at

Spencers Road 1,800

#

6.0 (May-Nov) Minimum passing flow 10 ML/d

Tarwin River West

Branch at Koonwarra

10.0 (May-Nov)

5.0 (Dec-Apr)*



*Summer diversion only available until 30 June 2015 as an interim measure – this has therefore not been included in

current yield estimates presented subsequently in this chapter.

#Less any water diverted to Korumburra under the Korumburra bulk entitlement from the Tarwin River West Branch.

This supply to Korumburra is currently complex and difficult to operate and only suitable for use in severe drought, so

volumes diverted to Korumburra are expected to be zero in almost all years and up to several hundred megalitres in a

drought year.

During the 2006/07 water year, temporary pumping occurred from the Tarwin River West Branch

to Korumburra and Leongatha. This was formalised into a qualification of rights to the Meeniyan

bulk entitlement on 13 June 2008 prior to being incorporated into an amendment to the

Korumburra and Leongatha bulk entitlements on 19 October 2010. The Current Operation and

Infrastructure scenario for the WSDS assumes that winter pumping from the Tarwin River West

Branch to Korumburra and Leongatha occurs in accordance with the amended bulk entitlement, but

at the current diversion infrastructure capacities, which are lower than those allowable in the bulk

entitlement amendment. No summer pumping is assumed. Further detail on the assumed operation

of the diversion from these sources is shown in Table 9-3, which assumes current diversion

infrastructure capacities. Full use of the amended entitlement by upgrading diversion infrastructure

capacities is discussed as a supply enhancement option later in this document (Section 12.2.3).

Table 9-3 Tarwin River West Branch Diversion Rules for Current Operation and Infrastructure Scenario

Pumping Rule


(pumping to Ruby Creek Storages and Ness Gully

Storage)

Coalition Creek at pump site (pumping to Ruby Creek

Storages)


100 10





Capacity Sharing (Ruby Ck No 4 : Ness Gully No. 2)

3 ML/day maximum to Leongatha, 3 ML/day maximum to

Korumburra(1)

To Ruby Creek Storages(2)

Pipe capacities 5 ML/d at extraction point. 3ML/d to Ness Gully, 3ML/d to Ruby Ck

storages

5 ML/d


(2) Modelling assumes supply to No.4 reservoir. Current connection only extends to No. 3 reservoir, but temporary

pumping arrangements could transfer up to No. 4 reservoir if required in practice.

There are several groundwater bores in the Leongatha area. The Current Operation and

Infrastructure scenario in the WSDS assumes that groundwater pumping occurs as per the rules

outlined in Table 9-4. These rules incorporate the licence conditions on the groundwater licence

issued by Southern Rural Water in 2010, but conservatively assume that only 1.0 ML/d can be

sustained from the bores rather than the 2.1 ML/d that has been licensed. Additional pumping

above 1.0 ML/d may occur as an emergency supply measure in extreme drought.

Table 9-4 Groundwater Pumping Rules for Current Operation and Infrastructure Scenario

Pumping Rule Bores supplying Leongatha only Bores supplying both Leongatha

and Korumburra(1)

Bores S9025900/2, 138891 and S9026806/1

S9029805/2

Total extraction rate (ML/d) 0.5 0.5

Relevant storages that trigger pumping

Ruby Creek All storages in Leongatha and Korumburra system

Bore pumping triggers During the period Oct-Dec: relevant storages at 75% of capacity triggers pumping to start and stop

During the period March-May: relevant storages <50% of capacity triggers pumping to start, and 75% of capacity triggers pumping to stop



Melbourne system to potentially supply Leongatha when the desalination plant at Wonthaggi has

been commissioned. A physical connection between Leongatha and the Melbourne supply does

not currently exist, so this supply source could only be accessed if South Gippsland Water decides

to connect Leongatha to the Melbourne system.


Leongatha had a population of 4202 people excluding visitors in the 2006 census (DPCD, 2009).

Separate population data is not available for Koonwarra. A demand model was fitted to the recent

unrestricted data to estimate long-term average annual demand, which takes into account how

current demands would vary under a wider range of natural climate variability. The historical and

estimated long-term current demand is shown in Figure 9-2. The estimated long-term current

demand for Leongatha and Koonwarra is 1,893 ML/yr at South Gippsland Water‟s treatment plant

inlet, of which around 12% is utilised on average through the treatment plant. The variation in

demands throughout the year is shown in Figure 9-2, which shows that demand varies seasonally

with climate. There is a relatively high base demand due to the Murray Goulburn milk factory.

Murray-Goulburn demand currently accounts for around 70% of total water use at Leongatha.

Figure 9-2 Long-term monthly demands for Leongatha and Koonwarra


Leongatha has experienced regular restrictions over recent years. This included restrictions in

1997/98, 2002/03, and from 2005/06 to 2007/08. Stage 4 (of 4 stages) restrictions were

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implemented in 2006/07. Since 2006/07 the supply and demand balance has been improved

through a reduction in demand, increases in groundwater supply, additional supply from the Tarwin

River West Branch and the development of revised restriction triggers. Reliability of supply

modelling over the period July 1950 to June 2007 indicated that restrictions would only have been

required in 4 of the last 57 years (93% annual reliability) under a repeat of historical climate

conditions, which meets South Gippsland Water‟s level of service objective for restrictions. The

minimum storage volume reached under this scenario was estimated to be 175 ML. Further details

on the water resource model used to assess reliability of supply (and yield) can be found in SKM

(2009).


Ruby Creek is a tributary of the lower Coalition Creek and the Tarwin River West Branch.

Information about the environmental condition of Ruby Creek is limited, however many of the

assessments and conclusions drawn in Section 8.3 about Coalition Creek and below about Wilkur

Creek are likely to be broadly representative of those expected for Ruby Creek. The main

difference between Ruby Creek and these neighbouring streams is the presence of Leongatha‟s four

water supply storages, which act as a fish barrier and significantly reduce streamflows in the creek

from natural flow conditions. Passing flow downstream of the reservoirs is 0.5 ML/d or natural

flow, whichever is lower. The presence of these reservoirs inhibits the ability to achieve ecological

improvements in Ruby Creek and lower Coalition Creek.

Information about the environmental condition of Tarwin River West Branch was assessed for

South Gippsland Water in SKM (2006b) Tarwin River Preliminarily Environment Assessment.

The main relevant outcomes were previously presented in the section on the ecological condition of

water sources for Korumburra, which is repeated below for ease of reference.









populations of Australian grayling in the Tarwin River immediately below the weir at Meeniyan.






Installation of a fish ladder at the weir at Meeniyan was identified as a priority by DSE (Justin

O‟Connor, pers. comm.) and has now been installed.

Water quality was found to be poor at the site on the West Branch of the Tarwin River near

Koonwarra and was above the State Environment Protection Policy guideline values.

The above assessment was confirmed in the environmental flow assessment for the Tarwin River

West Branch in SKM (2009). The environmental flow assessment linked the provision of low

flows to maintaining habitat in pools for river blackfish, to maintain habitat, to allow fish

movement, and to provide moisture for riparian and fringing plants. Summer freshes were

important for preventing colonization of riparian areas by terrestrial plants, to entrain organic

matter and transport nutrients downstream, whilst slightly higher, short duration transitional flows

in summer were considered important for triggering fish migration. Winter low flows were

designed to maintain habitat, inundate paperbarks and prevent colonisation of weeds, while high

flow freshes were intended to maintain channel forming processes and to facilitate the upstream

migration of Tupong and juvenile fish species, including Australian Grayling and Galaxiids.

Bankfull flows were recommended to maintain channel forming processes and no overbank flows

were specifically recommended.

Information about the environmental condition of Coalition Creek was assessed for South

Gippsland Water in SKM (2006a) Coalition Creek Preliminarily Environment Assessment. The

key outcomes of that assessment of relevance to the WSDS are:

The creek flows through a predominantly rural setting through land that has been cleared for

dairy farming.

Many sections of the creek are infested with willows and other weeds, however some willow

removal has occurred and revegetation at these sites is now starting to provide shade to the

creek.



months.



The creek ceases to flow in summer, but in some areas there are permanent water pools which

are an important summer refuge for aquatic fauna. Any premature drying of the pools due to

changes in summer flow regime could impact on ability of small bodied fish to avoid larger

predatory species.



In a previous fish survey, no native fish species were found in the creek. Access to Coalition

Creek by many of the native migratory fish in the Tarwin River catchment would be limited by

flow regime and existing fish barriers.

The above assessment was confirmed in the environmental flow assessment for Coalition Creek in


connectivity between pools, maintaining water quality in pools and to provide moisture for riparian

and fringing plants. Summer freshes were important for preventing colonization of riparian areas

by terrestrial plants, to entrain organic matter and transport nutrients downstream. Winter low

flows were designed to maintain habitat and prevent colonisation of weeds, while high flow freshes


Tupong and juvenile fish species. Bankfull flows were recommended to maintain channel forming

processes and no overbank flows were specifically recommended.



Historical demands for Leongatha and Koonwarra have remained relatively stable since 1993, as

can be seen in Figure 9-3. These demands are recorded at the clear water storage outlet and do not

include an allowance for treatment plant utilisation. Restrictions have affected demand over much

of the recent period.

The number of customers billed in this supply system has however increased over the last few

years, as shown in Figure 9-3. This potentially indicates that significant water savings have been

achieved by South Gippsland Water and its customers in recent years. Major industrial demand for

water at Leongatha has remained relatively constant over the last three years, but was slightly lower

in the 2006/07 drought. This potentially indicates that proposed water savings at Murray Goulburn

have not yet resulted in a reduction in demand for water at the factory.

Figure 9-3 Historical demands and number of customers billed at Leongatha and Koonwarra

The population of Leongatha has grown steadily over the last two decades, as shown in Figure 9-4,

with the total population increasing from 3,620 in 1981 to 4,202 in 2006. The number of dwellings

has also increased at a similar rate.

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Figure 9-4 Historical population in Leongatha and Koonwarra






covering South Gippsland Water‟s water supply area. Leongatha and Koonwarra are located

within the South Gippsland Shire Central SLA and accounts for around 33% of the population

within the SLA.

A comparison of the 2006 census results against the previous population projections from the 2001

census indicated that both the Victoria in Future and the Local Growth overestimated population

growth between 2001 and 2006. The Victoria in Future projections were closer to the growth

which actually happened, which was an increase in population of 3% for the supply system. Given

the uncertainty of future population, South Gippsland Water has considered two population

forecasts, which include the Victoria in Future projections and a higher Local Growth scenario that

allows for faster growth in urban centres within SLAs.

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year. Future Murray Goulburn demand was previously discussed in Section 4.5 and involves two

anticipated water saving phases in the short-term with a total annual demand reduction of 440 ML.

The Local Growth scenario assumes a 1.5% annual growth rate in residential demand over the

planning horizon. It also assumes that Murray Goulburn demand only drops by 67 ML to 1000 ML

and that a further 500 ML of industrial demand occurs in the year 2025.










evaporation. Under the ongoing low flow conditions scenario, total inflows to the Leongatha

storages have been reduced by 52% prior to July 1997.

The Current Operation and Infrastructure water supply and demand situation for the Ruby Creek

system is shown in Figure 9-5. This figure illustrates that Victoria in Future demand is not

expected to exceed supply at South Gippsland Water‟s level of service objective if Murray

Goulburn achieves its anticipated reduction in demand of 440 ML/yr from water savings. If

Murray Goulburn‟s anticipated demand reduction is only partially realised and demands only drop

by 67 ML/yr (to 1,000 ML/yr) in Stage 1 of Murray Goulburn‟s demand reduction measures in

2010/11, then Victoria in Future demand would exceed supply at South Gippsland Water‟s level of

service objective between 2040 and 2044 under the two alternative climate scenarios. Under the

Local Growth demands, which assume the same 67 ML/yr reduction initially but then no further

reduction in demand from Murray Goulburn, demand would exceed supply at South Gippsland

Water‟s level of service objective at around the year 2015 under medium climate change

conditions. Demand currently exceeds available supply at South Gippsland Water‟s level of service

objective under the ongoing low flow conditions scenario.

Figure 9-5 Current Operation and Infrastructure Water Supply and Demand for Leongatha and Koonwarra


Three potential land use changes with the catchments supplying Leongatha and Koonwarra were

investigated to understand the potential risk they could pose to available supply.

Bushfires: Only 14% of the Ruby Creek catchment has vegetation cover. This means that the risk

of catchment yield decreasing significantly due to the effects of bushfires is low. There is no




Plantations: There are no significant plantations in the water supply catchment for this supply

system.


If the additional demand reduction options outlined in Section 4.10 are adopted for Leongatha and

Koonwarra, the spare yield available would increase, as shown in Figure 9-6. Under the Local

Growth scenario, this highlights the benefit of demand reduction measures in reducing the size of

any future supply augmentations.

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Victoria in Future demand under medium climate change with Murray Goulburn demand reduction realised

Victoria in Future demand under medium climate change with Murray-Goulburn demand reduction partially realised




Figure 9-6 Effect of additional demand reduction options for Leongatha and Koonwarra

9.7. Summary of supply and demand for Leongatha and Koonwarra with current operation and infrastructure

In summary for Leongatha and Koonwarra under the Current Operation and Infrastructure supply

and demand scenarios:

Existing supply just meets South Gippsland Water‟s current level of service objectives under

the medium climate change scenario, but does not meet those objectives under the ongoing low

flows scenario;

Demand for water is not expected to exceed available supply at South Gippsland Water‟s level

of service objectives over the 50 year planning horizon if Murray Goulburn achieves its

anticipated water savings. If Murray Goulburn does not achieve these water savings then

demand would be expected to exceed supply at South Gippsland Water‟s level of service

objectives under the medium climate change scenario by around 2015;

Demand for water has fallen in recent years, whilst population and the number of dwellings

have increased; and


some form of supply enhancement will still be required over the 50 year planning horizon if

Murray Goulburn does not achieve its anticipated water savings.

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Victoria in Future demand under medium climate change with Murray-Goulburn demand reduction partially realised

Victoria in Future demand under medium climate change with Murray-Goulburn demand reduction partially realised and future demand reduction measures





South Gippsland Water‟s strategy to address the potential future supply shortfall under the Local

Growth scenario is presented in Section 12.

10. Supply and Demand Projections for Wonthaggi, Cape Paterson and Inverloch with Current Operation and Infrastructure

10.1. Introduction

This section of the WSDS outlines the supply and demand projections for Wonthaggi, Cape

Paterson and Inverloch over the next 50 years assuming current operation and infrastructure. It

includes an overview of the current supply system configuration, current demand for water and

current supply. It also includes supply and demand projections under future climate change and

alternative growth scenarios over the 50 year planning horizon. South Gippsland Water‟s response

to any shortfall in demand under the current operation and infrastructure scenarios is presented in

Section 12 in conjunction with nearby towns.



The source of supply for the Wonthaggi/Inverloch system is from the 4,200 ML Lance Creek

Reservoir. The dead storage is 960 ML but is reduced to 200 ML when a temporary pump is

installed, as occurred in 2006/07. A treatment plant located at Lance Creek Reservoir services

supplies to Wonthaggi, Inverloch and Cape Paterson. Water from the reservoir gravitates 4 km

downstream via a 34.4 ML/d capacity pipeline to the junction with the Inverloch supply pipeline.

It then travels a further 9 km via an 18.6 ML/d capacity pipeline to a 9 ML low level storage basin

at the junction with the Wonthaggi-Cape Paterson pipeline.

The main supply to Inverloch consists of one 18.4 ML/d gravity main from the Inverloch junction

to a 7.5 ML storage tank. Flow is boosted to the storage tank in peak demand periods. From the

tank, flow gravitates directly to Inverloch‟s reticulation system via a 10.7 ML/d capacity pipeline.

Pumping stations, located adjacent to the 9 ML low level concrete-lined service basin at the

Wonthaggi-Cape Paterson junction, supply the townships of Wonthaggi at a rate of 16 ML/d and

Cape Paterson at a rate of 8 ML/d.

A temporary diversion pump and pipeline was used in 2006/07 to divert water from the Powlett

River at Wonthaggi to Lance Creek Reservoir, which can now be operated annually as a winterfill

diversion.

A schematic of the supply system is shown in Figure 10-1.

Figure 10-1 Lance Creek Water Supply System Schematic


The bulk entitlement for Wonthaggi/Inverloch allows South Gippsland Water to divert up to a

maximum of 3,800 ML/yr from Lance Creek and 1,800 ML/yr from the Powlett River. The bulk

entitlement details are shown in Table 10-1 and Table 10-2.

Table 10-1 Bulk entitlement volume for Lance Creek

Source Maximum

annual volume

(ML/yr)

Maximum

diversion rate

(ML/d)


Lance Creek 3,800 35 100 ML/yr when Lance Creek storage

greater than 3,000 ML in December (wet

years). No daily minimum passing flow.

Powlett River 1800 10 As per Table 10-2. Winterfill diversions

only.

Table 10-2 Powlett River bulk entitlement

Flow in the Powlett River

upstream of offtake, F (ML/d)


(ML/d)


> 17 10 F – 10

12 – 17 5 F – 5

< 12 0 F

Note: F = flow in the Powlett River upstream of the offtake in ML/d.


Melbourne system to potentially supply Wonthaggi, Cape Paterson and Inverloch when the

desalination plant at Wonthaggi has been commissioned. The desalination plant is due to be

commissioned by July 2012. A physical connection of 10 ML/d between Lance Creek and the

Melbourne supply has been constructed and can be used to access the Melbourne supply.


Wonthaggi, Cape Paterson and Inverloch had populations of 6,191, 615 and 3,400 respectively in

the 2006 census excluding visitors (DPCD, 2009). This corresponds to a total of 10,206 for the

three towns. An additional 4,000 to 5,000 tourists are located in these towns in the summer

months. A demand model was fitted to the recent unrestricted data to estimate a long-term average

annual demand, which takes into account how current demands would vary under a wider range of

natural climate variability. The historical and estimated long-term current demand is shown in

Figure 10-2. The estimated long-term current demand is 1,706 ML/yr at South Gippsland Water‟s

treatment plant inlet, of which around 7% is utilised on average through the treatment plant. The

variation in demands throughout the year is shown in Figure 10-2, which shows that demand varies

seasonally with climate, with peak monthly demands being around double those in winter.

Figure 10-2 Long-term monthly demands for Wonthaggi, Cape Paterson and Inverloch


Prior to 2005, there were no instances of water restrictions in this supply system. From 2005 to

2009 there has been some form of restriction in every year, including Stage 4 restrictions in

2006/07. Part of the reason for severe restrictions in 2006/07 was due to the need to provide

emergency supply to Westernport Water. The volume of dead storage in Lance Creek Reservoir

has been reduced due to the use of a temporary pump, and drought response triggers were adjusted

accordingly. The supply system is currently meeting South Gippsland Water‟s level of service

objectives. Reliability of supply modelling over the period July 1892 to June 2007 indicated no

restrictions would have been required at current demands over this historical climate period. The

minimum storage reached was estimated to be 2115 ML. Further details on the water resource

model used to assess reliability of supply (and yield) can be found in SKM (2009).


Lance Creek is a tributary of the Powlett River. It is a small (1-4m wide) creek with high steep

banks. Downstream of the Lance Creek Reservoir it is deeply entrenched in flat farmland, with

riparian vegetation of swamp paperbark, blackberry and wattles (DPI, 2007). The creek has riffles

up to 20cm deep, and small pools up to 70 cm deep. There is good habitat for small native fish but

no information is available on fish species present (DPI, 2007). There are no Index of Stream

Condition sites located on the creek. It is difficult to assess the impact of a change in flow on the

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condition of Lance Creek as detailed data on the flora and fauna is limited. However, the main

risks to the aquatic fauna and flora in Lance Creek are probably from reduced flows during summer

that may result in degradation of water quality and loss of connectivity between pools.

Two Index of Stream Condition (ISC) sites on the Powlett River were assessed in 2004. The site

below Foster Creek was given a rating of moderate. Water quality data recorded in the Powlett

River downstream of Foster Creek (gauge# 227236) and at Wonthaggi (gauge #227254) indicated

that water quality in the river is poor and exceeds the recommended State Environment Protection

Policy (Victorian Government, 2003) guideline values for most parameters.

An environmental flow assessment of the Powlett River downstream of South Gippsland Water‟s

offtake near Wonthaggi was undertaken in Alluvium (2008). The environmental flow assessment

linked the provision of low flows to maintaining habitat in pools for eels, galaxias, tupong,

gudgeon and pygmy perch, as well as providing refuge from trout for small fish, preventing water

quality decline, providing fish migration and maintaining clonal spread of swamp paperbark.

Summer freshes were important for maintaining water quality, species migration, sediment

transport, nutrient entrainment, sexual recruitment of swamp paperbark and to facilitate

colonization of rushes and reeds. High flow freshes were and bankfull flows were considered to

provide similar benefits to low flow freshes, but also promote fish migration and trigger spawning.

No overbank flows were recommended due to the absence of identifiable ecological values on the

floodplain.

No environmental flow recommendations were set for the Powlett River estuary in Alluvium

(2008), however the report emphasised the importance of flow events to maintain estuary

processes, such as keeping the estuary mouth open and periodically inundating salt marsh

communities with fresh water.



Historical diversions to Wonthaggi, Cape Paterson and Inverloch have remained relatively stable

since 1992, as can be seen in Figure 10-3. These diversions are recorded at the clear water storage

outlet and do not include an allowance for treatment plant utilisation since the plant became

operational in 1997. Restrictions have affected demand over much of the recent period, however in

2008/09 restrictions were only in place for 6 weeks in winter, which means that data in that year

was largely unrestricted.

The number of customers billed in this supply system has however increased in this supply system

over the last few years, as shown in Figure 10-3. This potentially indicates that significant water

savings have been achieved by South Gippsland Water and its customers in recent years. The

demand for the largest industrial water user in the supply system has remained relatively constant

since 2006/07.

Figure 10-3 Historical diversions and number of customers billed at Wonthaggi, Cape Paterson and Inverloch

The populations of all three towns have grown significantly over the last two decades, as shown in

Figure 10-4, with the total population increasing from 6,368 in 1981 to 10,206 in 2006. Between

the 2001 census and 2006 census there was a slight decline in total population, which was due to a

reduction in residents at Inverloch. The number of dwellings was however shown to increase from

2001 to 2006.

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Figure 10-4 Historical population in Wonthaggi, Cape Paterson and Inverloch





stronger growth within towns at a rate greater than the surrounding SLA. There are five SLAs

covering South Gippsland Water‟s supply area. Wonthaggi, Cape Paterson and Inverloch are

located within the Bass Coast Shire Balance SLA and account for around 55% of the population

within that SLA.


from the 2001 census indicated that both the Victoria in Future and the Local Growth


closer to the change in population recorded in the census data, which was a decline in population of

less than 1%. Given the uncertainty of future population, South Gippsland Water has considered

two population forecasts, which include the Victoria in Future projections and a higher Local

Growth scenario that allows for faster growth in urban centres within SLAs.

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year. No growth in major industrial demand was assumed to occur. The Local Growth scenario

assumes a 3.0% annual growth rate in residential demand to the year 2030, decreasing to a 2.5%

annual growth rate thereafter over the planning horizon. It also assumes a 10% increase in major

industrial demand in the year 2015 and a further 10% increase in the years 2025 and 2055.










evaporation. Under the ongoing low flow conditions scenario, Lance Creek streamflows upstream

of Lance Creek Reservoir have been reduced by 42% prior to July 1997.

The Current Operation and Infrastructure water supply and demand situation for the Lance Creek



accordance with Victoria in Future population projections, supply will be sufficient to meet

demands at South Gippsland Water‟s level of service objectives over the 50 year planning horizon.

For the higher Local Growth scenario, which is also shown in Figure 10-5, augmentation of the

supply system would be required between 2046 and 2052, depending on climate conditions.

Figure 10-5 Current Operation and Infrastructure Water Supply and Demand for Wonthaggi, Cape Paterson and Inverloch


Three potential land use changes within the catchments supplying Wonthaggi, Cape Paterson and

Inverloch were investigated to understand the potential risk they could pose to available water

supply.

Bushfires: Only 5% of the Lance Creek catchment has vegetation cover. This means that the risk

of catchment yield decreasing significantly due to the effects of bushfires is low. There is no record

of bushfires occurring in the catchment over the last few decades.




Further comments on the sensitivity of the Current Operation and Infrastructure projections to

demand uncertainty are also presented.

Future development: Advice from the Bass Coast Shire is that an increase in the population at

Wonthaggi of 3000-3500 people is expected over the next 15-20 years, with growth at Cape

Paterson and Inverloch being contained to a modest increase. These population increases are

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Supply from existing Melbourne supply pipeline in 2011/12

within the Victoria in Future projections used in the WSDS, which estimate an increase in

population for the three towns of around 4,700 people from 2006 to 2022 (roughly a 15-20 year

period).

The Minister for Planning (2009) made an assessment of the Environmental Effects Statement of

the desalination plant at Wonthaggi. The Minister concluded that whilst there may be a short-term

increase in the population of surrounding towns by several hundred people during the construction

phase of the project, most of these people could be accommodated within existing accommodation.

After completion of construction, ongoing accommodation would be required for in the order of

30-50 workers plus their families, which is a small percentage (<1%) of the current population in

surrounding towns. It is therefore concluded that no specific adjustments need to be made to

population projections for the desalination plant workforce.


If the additional demand reduction options outlined in Section 4.10 are adopted for Wonthaggi,

Cape Paterson and Inverloch, the demand over the planning horizon would be reduced as shown in

Figure 10-6.

Figure 10-6 Effect of additional demand reduction options for Wonthaggi, Cape Paterson and Inverloch

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10.7. Summary of the supply and demand for Wonthaggi, Cape Paterson and Inverloch with current operation and infrastructure

In summary for Wonthaggi, Cape Paterson and Inverloch under the Current Operation and

Infrastructure supply and demand scenarios:

Existing supply meets South Gippsland Water‟s current level of service objectives;

Demand for water over the 50 year planning horizon is not expected to exceed available supply

at South Gippsland Water‟s level of service under the Victoria in Future growth scenario.

Under the local growth scenario, demand is not expected to exceed available supply at South

Gippsland Water‟s level of service until between the years 2046 to 2052, depending on climate

change assumptions;

Demand for water has fallen in recent years, whilst population and the number of dwellings

have increased; and

Demand reduction initiatives will increase the spare yield available at the end of the 50 year

planning horizon under the Victoria in Future growth scenario and will reduce the magnitude

of any future supply enhancement under the Local Growth scenario.

South Gippsland Water‟s strategy to address the potential future supply shortfall under the Local

Growth scenario is presented in Section 12.

11. Supply and Demand Projections for Unserviced Towns near Inverloch with Current Operation and Infrastructure

11.1. Introduction

This section of the WSDS outlines the demand projections for unserviced towns near Inverloch

over the next 50 years assuming current operation and infrastructure. These towns include the

existing towns of Venus Bay and Tarwin Lower. None of these towns are currently supplied by

South Gippsland Water. These towns are expected to have sufficient demand for water within

close proximity to an existing supply system to make their supply by South Gippsland Water

financially feasible, particularly given the Melbourne supply connection to the nearby Lance Creek

system. Venus Bay is only around 10 km from Inverloch, but is separated by the Tarwin River

estuary.

South Gippsland Water‟s response to supplying these unserviced towns is presented in Section 12

in conjunction with nearby serviced towns.



Existing unserviced towns rely upon rainwater for their supply. New developments would need to

identify a source of water supply as part of their planning activities.


Residents in the unserviced towns can harvest rainwater in rainwater tanks. The availability of

other entitlements, such as groundwater licences, is unknown.


Venus Bay and Tarwin Lower had populations of 440 and 107 respectively in the 2006 census

excluding visitors (DPCD, 2009). This corresponds to a total of 547 for the two existing towns.

Large numbers of tourists are located in these towns in the summer months. The current demand

for individual towns and developments was previously presented in Section 4.8. The current

demand from Venus Bay and Tarwin Lower is estimated to be 280 ML/yr. This figure excludes

Harmers Haven and a future lot development at the RACV club, which are assumed to be already

incorporated into the Victoria in Future demand projections for the Lance Creek system because of

their proximity to the existing towns.


Existing supply consists of privately owned rainwater tanks. It is estimated that reliability of

supply could be improved by connection to a supply source managed by South Gippsland Water.


The environmental condition of the rivers supplying the Lance Creek system was previously

discussed in Section 10.3.



The population at Venus Bay has grown significantly over the last two decades, as shown in Figure

11-1. The population at Tarwin Lower, which has only been collected since the 2001 census,

declined slightly between 2001 and 2006. Current population for the two existing towns is 107

people at Tarwin Lower and 440 people at Venus Bay excluding visitors. The number of dwellings

has increased significantly between each census over the last two decades.

Figure 11-1 Historical population in Venus Bay and Tarwin Lower

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Dwellings - Venus Bay and Tarwin Lower

Population - Venus Bay and Tarwin Lower

Note: Tarwin Lower data only available from 2001 census onwards





stronger growth within towns at a rate greater than the surrounding SLA. For the existing towns of

Venus Bay and Tarwin Lower, the growth projections for Wonthaggi, Cape Paterson and Inverloch

have been adopted.





The anticipated demand at the end of the 50 year planning horizon is estimated to be

700-1000 ML/yr, depending on growth assumptions.

Figure 11-2 Current Operation and Infrastructure water demand for unserviced towns near Inverloch

11.4.3. Future supply projections

Supply projections are considered in Section 12 as part of the strategy for Wonthaggi, Cape

Paterson and Inverloch. The timing of the connection of the unserviced towns to South Gippsland

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Water‟s supply systems is uncertain and it has been assumed in the strategy that it could occur

around the year 2025. This would allow sufficient time for South Gippsland Water to undertake its

planning and design activities and then construct and commission the new supply system.


Three potential land use changes within the catchments supplying Wonthaggi, Cape Paterson and

Inverloch were investigated to understand the potential risk they could pose to available water

supply. These were previously documented in Section 10.5 and indicated that the risk of changes

in supply due to bushfires, logging and plantations in the Lance Creek catchment was low.


If the additional demand reduction options outlined in Section 4.10 were adopted for Venus Bay

and Tarwin Lower, the size of any future supply augmentation option could be minimised, as

shown in Figure 11-3. This highlights the benefit of demand reduction measures in delaying the

need for augmentation works for the Lance Creek system, which is the nearest supply source

managed by South Gippsland Water.

Figure 11-3 Effect of additional demand reduction options for unserviced towns near Inverloch

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11.7. Summary of the supply and demand for unserviced towns near Inverloch with current operation and infrastructure

In summary for unserviced towns near Inverloch under the Current Operation and Infrastructure

supply and demand scenarios:

Existing supply consists of privately owned bores and rainwater tanks;

Population and the number of dwellings have increased significantly over the last two decades.

The number of people currently permanently residing in Venus Bay and Tarwin Lower is 547;

and

Demand for water is estimated to currently be in the order of 280 ML/yr, rising to between

700-1,000 ML/yr over the 50 year planning horizon;

South Gippsland Water‟s strategy to address the potential future supply is presented in Section 12.

12. Strategy for South Gippsland Water’s Northern and Southern Towns

12.1. Introduction

This section of the document presents the demand reduction and supply enhancement strategy for

towns west of the Tarwin River in South Gippsland Water‟s northern and southern regions. These

towns include Poowong, Loch, Nyora, Korumburra, Leongatha, Koonwarra, Cape Paterson,

Inverloch and Wonthaggi. The strategy for these towns is considered collectively, because one of

the supply options involves sourcing water for all of these towns from the Melbourne supply

system. The ability to supply Venus Bay and Tarwin Lower is also presented in this chapter.

The pros and cons of two strategies were considered by South Gippsland Water:

Supply from existing separate South Gippsland Water headworks – This strategy involves

upgrading South Gippsland Water‟s existing supply infrastructure and operating the supply systems

for South Gippsland Water‟s northern and southern towns independently. Details of this strategy

for each town are presented in Section 12.2.

Supply from Melbourne – This strategy involves connecting both northern and southern towns to

a single supply system sourced from a combination of Lance Creek Reservoir (prime source) and

connection to the Melbourne supply system. Much existing supply system infrastructure for the

Northern Towns would be decommissioned. Details of this strategy for each town are presented in

Section 12.3.

When outlining each strategy, infrastructure has been sized to meet the requirements of the Victoria

in Future demand projections, with the Local Growth scenario being used to test the robustness of

the strategy under a higher growth rate.

A sustainability assessment comparing the strategies is presented in Section 12.4 followed by an

action plan for South Gippsland Water in Section 12.5.

12.2. Supply from existing South Gippsland Water headworks

12.2.1. Supply from existing South Gippsland Water headworks for Poowong, Loch and Nyora

Available supply to Poowong, Loch and Nyora is not sufficient to cater for immediate future

demands at South Gippsland Water‟s level of service objectives, even after considering additional

demand reduction. Hence the Poowong, Loch and Nyora system will require supply enhancement.

A range of supply enhancement options were considered in SKM (2004), which were narrowed in

the 2007 WSDS (South Gippsland Water, 2007) to focus on the preferred option to raise Little Bass

Reservoir by 2 metres.

Increasing the height of the dam wall in the Little Bass Reservoir by approximately 2m would

increase the storage capacity by approximately 200 ML. This additional storage volume would

then be used to harvest additional winter flows of 118 ML/yr under the Sustainable Diversion Limit

available from the catchment upstream of the reservoir. This would require separate accounting of

water in the additional storage. This additional winterfill volume would be accumulated over

several years and then utilised in dry years. The yield increase from this action is shown in Figure

12-1. This increase in supply would be sufficient to meet the supply needs of Poowong, Loch and

Nyora over the planning horizon of fifty years under Victoria in Future growth rates. At a higher

growth rate, additional augmentation would be required after the year 2044, suggesting that this

supply enhancement option is mildly sensitive to growth forecasts. A summary of the effect of this

local supply enhancement option for Poowong, Loch and Nyora is shown in Figure 12-1.

Undertaking this supply enhancement may also improve the opportunities for connecting Little

Bass Reservoir to the Korumburra system and utilising this additional water in Korumburra whilst

Poowong, Loch and Nyora are still growing. This is dependent upon future water supply options

for Leongatha and Korumburra, which are largely dependent on the future water supply needs of

the major industrial customers in those towns. These industries find it difficult to provide demand

projections for a 10 year planning horizon and are not able to underwrite an expansion in the water

supply system with a 50 year or more service life. Linking the Little Bass supply system to

Korumburra would not increase the reliability of supply or yield for Poowong, Loch and Nyora.

Figure 12-1 Supply from Existing South Gippsland Water Headworks for Poowong, Loch and Nyora

The resilience of this augmentation option to severe prolonged drought was examined by

estimating supply system behaviour under a repeat of the 2006/07 severe drought year. This

analysis highlighted that even though local catchment inflows were negligible in this year from

December to April, the availability of a large volume in storage relative to demand meant that

South Gippsland Water is expected to be able to maintain supply through two consecutive years of

repeating 2006/07 climate.

The alternative to this local supply enhancement option involves connection to the Melbourne

supply system, which is presented in Section 12.3.1.

12.2.2. Supply from existing South Gippsland Water headworks for Korumburra

Available supply to Korumburra is not sufficient to cater for immediate future demands at South

Gippsland Water‟s level of service objectives, even after considering additional demand reduction.

Hence the Korumburra system will require supply enhancement. Water supply options for

Korumburra were previously outlined in SKM (2004) and South Gippsland Water (2007) and

included raising the existing storage, supplying water from Melbourne, supplying water from the

Little Bass Reservoir and being able to permanently supply water from the Tarwin River via

Leongatha. It was concluded from that analysis that raising the existing storages supplying

Korumburra would be the most appropriate local supply option, combined with connecting Little

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Yield under medium climate change with supply enhancement

Yield under ongoing low flow conditions with supply enhancement

Raise Little Bass Reservoir by 2 m

Spare yield potentially available to Korumburra in short to medium term

Supply from Melbourne system under local growth scenario

Bass Reservoir to Bellview Creek Reservoir. Any supply enhancement options should allow a

buffer for potential increases in major industrial demand where it is feasible and cost-effective to

do so.

Bellview Creek is located in the Bass River catchment, which does have some available winterfill

volume available under Sustainable Diversion Limits. Increasing total storage in the Korumburra

supply system by around 200 ML could be used to harvest additional winter flows under the

Sustainable Diversion Limit to increase yield by around 90 ML. This would still fall well short of

Korumburra‟s long-term water needs. The Bellview Creek Reservoir requires remedial works to

ensure structural stability of the embankment, with those works programmed to occur around 2018

to 2020. There may be cost savings in raising the embankment and spillway at the same time as

remedial works are carried out, as opposed to the cost of raising the embankment and spillway

level at a subsequent time. The exact additional volume to which the storages could feasibly be

raised would need to be confirmed by geotechnical investigations. South Gippsland Water secured

a bulk entitlement amendment in October 2010 to raise the capacity of the Korumburra storages by

200 ML.

The increase in storage volume in the Korumburra supply system and the raising of Little Bass

Reservoir would allow water from Little Bass Reservoir to be transferred across to the Korumburra

supply system. It is estimated that around 200 ML/yr could be transferred through this mechanism

over the next few decades, dependent on the rate of growth in Poowong, Loch and Nyora.

Since drafting the previous WSDS in 2007, the supply from the Tarwin River West Branch has

been developed, which presents an alternative local supply enhancement option. Additional supply

from the Tarwin River West Branch is permitted under the conditions of the bulk entitlement

amendment obtained by South Gippsland Water in October 2010. This option provides less supply

to Korumburra than the Little Bass Reservoir connection because the proposed upgrade of the

Tarwin River West Branch supply infrastructure up to the entitlement volumes primarily benefits

Leongatha rather than Korumburra. As mentioned previously, the infrastructure in place to transfer

water from Leongatha to Korumburra utilises existing obsolete infrastructure that is complex and

difficult to operate, and is currently only suitable for use in a severe drought.

A summary of the local supply enhancement option for Korumburra is shown in Figure 12-2 with

Little Bass Reservoir connected to Korumburra. This option assumes an initial connection to the

Little Bass Reservoir in 2013/14 (with Little Bass Reservoir capacity also being increased by

200 ML), followed by an additional 200 ML of storage at Bellview Creek Reservoir in 2017/18

when this reservoir is scheduled for a dam safety upgrade. It can be seen from this figure that this

local supply enhancement option will provide adequate supply over the planning horizon under

Victoria in Future growth projections. However it is evident that if the Local Growth scenario

were to come to fruition, this supply option would not be capable of maintaining supply at South

Gippsland Water‟s level of service objective without requiring a second supply augmentation over

the planning horizon. A connection to the Melbourne supply system would be required around

2035 under the Local Growth scenario.

Figure 12-2 Supply from Existing South Gippsland Water Headworks for Korumburra



analysis highlighted that local catchment inflows were negligible throughout most of this year and

considerably less than available storage capacity and annual demand. Transfers were modelled to

occur from the Little Bass Reservoir, however the volume of the transfers was small in order to

maintain storage in Little Bass Reservoir. The outcome of this investigation is that South

Gippsland Water would be likely to struggle to maintain supply through two consecutive years of

repeating 2006/07 climate with this augmentation option at Korumburra and that the supply system

is vulnerable to prolonged severe drought. Emergency supply measures at Korumburra include the

use of groundwater bores and the temporary connection to the Tarwin River West Branch.

12.2.3. Supply from existing South Gippsland Water headworks for Leongatha and Koonwarra

Various supply enhancement options were considered in the 2007 WSDS, including linking

Leongatha to Korumburra and the Little Bass system, harvesting from the Tarwin River West

Branch, additional storage, supply from groundwater and pumping from Coalition Creek upstream

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Connect to Melbourne system under local growth scenario

Connect to Little Bass Reservoir in 2013/14

Upgrade Bellview Creek Reservoir 2017/18 in line with timing for dam safety requirements

of Ruby Creek. Since the 2006/07 drought, South Gippsland Water implemented a range of

drought response measures which have helped to clarify supply capability from these alternative

sources. The current system now includes updated groundwater supply and winter diversion from

the Tarwin River West Branch or Coalition Creek of up to 5 ML/d.

If Murray Goulburn can achieve water savings as anticipated, then no supply enhancement at

Leongatha will be required, as shown in Figure 12-3. In the event that Murray Goulburn only

partially achieves its anticipated water savings under the Victoria in Future projection, the Tarwin

River West Branch supply would need to be upgraded at around the year 2050/51. If population

growth occurs at the faster Local Growth rate, then additional supply enhancement could be

required in 5-10 years time. Upgrading the Tarwin River West Branch supply would provide only

a small increase in available supply but could lengthen the time to the next supply augmentation by

up to 5-10 years. If a step increase in major industrial demand were to occur, as has been

suggested in the Local Growth scenario, then additional supply enhancement would be required

when that step change occurs. The diversion capacities under the option to increase supply from

the Tarwin River West Branch are shown in Table 12-1, which include upgrading the diversion

pipe at the offtake from 5 ML/d to 10 ML/d, but no increase in the diversion capacity to

Korumburra. This increase in supply capacity could occur within the existing bulk entitlement.

Table 12-1 Tarwin River West Branch Diversion Rules under Enhanced Diversion Infrastructure Capacities

Pumping Rule


(pumping to Ruby Creek Storage 3 and Ness Gully Storage)

Coalition Creek at pump site (pumping to Ruby Creek Storage

3)


100 10





Pipe capacities 10 ML/d at extraction point. 10ML/d to Ruby Ck storages

6 ML/d, feeding into 10ML/d Tarwin extraction pipe to Ruby Ck

An option which was previously considered in the 2007 WSDS (South Gippsland Water, 2007)

involved constructing 1000 ML of additional storage on Ruby Creek and diverting from Wilkur

Creek. This volume is the practical limit to storage size in the Ruby Creek valley, beyond which

dam wall costs are likely to increase significantly. With the Tarwin River West Branch diversion,

the option of diverting additional water from Wilkur Creek is no longer available. This is because

the constraining Sustainable Diversion Limit catchment is downstream of both diversion locations.

The additional 1000 ML of storage supplied with diversions from the Tarwin River increases yield

by several hundred megalitres per year, but would still not be sufficient to meet the Local Growth

requirements for water over the 50 year planning horizon. Similarly if up to 2,000 ML of

additional storage is provided, modelling indicates that there are insufficient streamflows in most

years to fill a reservoir of this size, resulting in a supply system yield that is still insufficient to

meet future demands. This suggests that local supply enhancement options are likely to be of

limited long-term value to South Gippsland Water if growth in demand accelerates beyond Victoria

in Future projections.

The Leongatha Water Treatment Plant has a useful life up to around the year 2020. Maintaining

the existing headworks for Leongatha and Koonwarra would require the treatment plant to be

replaced at this time, which represents an additional cost relative to the Melbourne supply option

considered later in this chapter.

Figure 12-3 Supply from Existing South Gippsland Water Headworks for Leongatha and Koonwarra



analysis highlighted that local catchment inflows were negligible in this year from November to

May and considerably less than available storage capacity and annual demand. The outcome of

this investigation is that South Gippsland Water would be likely to struggle to maintain supply

through two consecutive years of repeating 2006/07 climate with this augmentation option at

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Victoria in Future demand under medium climate change with Murray-Goulburn demand reduction partially realised and future demand reduction measures



Yield under ongoing low flows with supply enhancement

Tarwin West branch pipe upgrades under local growth scenario

+1000 ML additional storage under local growth scenario

Melbourne suppply connection under local growth scenario

Under ViF growth no supply enhancement required

Tarwin West branch pipe upgrade under ViF growth if Murray-Goulburn demand reduction only partially achieved

Leongatha and that the supply system is vulnerable to prolonged severe drought. Emergency

supply measures at Leongatha include the use of groundwater bores.

12.2.3.1. Uncertainty in Murray Goulburn demand

The Murray Goulburn milk factory currently uses around 70% of the total water supplied in the

Leongatha system. Murray Goulburn has embarked on a $135 million upgrade of its factory to

improve efficiency of operations and to enable new products to be manufactured. It has introduced

water saving measures to date but the extent of water saving and reuse is limited by current cost

and technology. Murray Goulburn has announced that it will be proceeding with a $9.2 million

water recycling project at its Leongatha plant, with assistance from the State Government.

According to Murray Goulburn, this project would reduce Murray Goulburn‟s town water demand

by 220-400 ML in 2009/10, and a further 220 ML by 2012/13, which is a total of approximately

600 ML per annum by 2012/13 (B.Alcock, Murray Goulburn, pers.comm. 30/7/2009). Analysis of

metered supply to Murray Goulburn and the steam generation plant up to the end of 2009/10

suggests that the water savings anticipated by Murray Goulburn in 2009 have not yet translated into

a reduction in demand for water from South Gippsland Water‟s supply system. From South

Gippsland Water‟s perspective there is therefore some uncertainty surrounding future demand for

Murray Goulburn and hence it is essential that South Gippsland Water continue to communicate

with Murray Goulburn about their water needs and ability to conserve water on an ongoing basis.

12.2.4. Supply from existing South Gippsland Water headworks for Wonthaggi, Cape Paterson and Inverloch

The current Lance Creek supply system is very reliable, however forecast rapid growth in demand

for water in the region means that supply enhancement may be required in the future. A range of

supply enhancement options were considered in the 2007 WSDS (South Gippsland Water, 2007).

These included potential supply from Foster Creek and the Powlett River, and groundwater supply

from the Wonthaggi Coal Mines. The supply from the Powlett River was formalised into a bulk

entitlement amendment in 2009. Since the completion of that strategy document, the Victorian

State Government announced the construction of a desalination plant at Wonthaggi. A 10 ML/d

pipeline has been constructed and will connect the Melbourne supply to the Lance Creek system,

which can supply the towns of Wonthaggi, Inverloch and Cape Paterson. The availability of this

supply option provides a flexible, reliable and climate independent source of water. South

Gippsland Water‟s bulk entitlement for the Melbourne supply allows up to 1,000 ML/yr to be

diverted to Wonthaggi, Cape Paterson and Inverloch. Figure 12-4 shows that this existing supply

will be sufficient to meet demands over the 50 year planning horizon at South Gippsland Water‟s

level of service objective under the Victoria in Future growth projection. If growth occurs at the

higher Local Growth rate, then additional water would need to be sourced from the Melbourne

system from around 2050.

The proposed operation of the Melbourne supply is yet to be finalised. In the short-term it is

expected that South Gippsland Water will develop operational triggers that could be used to best

utilise the Melbourne supply after completion of the desalination plant. Those triggers would

ideally take into account the cost of the Melbourne supply, the cost of restrictions, customer

satisfaction associated with blending supply sources, and the physical ability to supply water from

the Melbourne system to each demand centre.

Figure 12-4 Supply from Existing South Gippsland Water Headworks for Wonthaggi, Cape Paterson and Inverloch




October to April, the availability of a large volume in storage and access to the Melbourne system

and Powlett River supplies means that South Gippsland Water would be able to maintain supply

through two consecutive years of repeating 2006/07 climate.

12.2.5. Supply from existing South Gippsland Water headworks for Unserviced Towns near Inverloch

Venus Bay and Tarwin Lower are expected to have sufficient demand for water within close

proximity to an existing supply system to make their supply by South Gippsland Water financially

feasible. Supply could be from the Lance Creek Reservoir or from the mid Tarwin River above the

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Additional supply from Melbourne system under local growth scenario


saline wedge. Venus Bay is only around 10 km from Inverloch, which would be the most likely

source of supply, but is separated by the Tarwin River estuary. Supply to the unserviced towns in

this area could result in additional water sales of around 280 ML/yr for South Gippsland Water,

rising to between 700-1,000 ML/yr in fifty years time, which would significantly increase South

Gippsland Water‟s customer base. It has been assumed for the purposes of developing the Water

Supply Demand Strategy that such demand would be supplied, but South Gippsland Water has no

defined timeframes for servicing this demand. Timeframes shown in Figure 12-5 are therefore

indicative only.

The ability of the Lance Creek supply system to meet demands from unserviced towns near

Inverloch was assessed. This has been done on the basis of 10 ML/d being available from the

Melbourne system, which is the current capacity of the transfer pipeline from the desalination

plant. Figure 12-5 shows that after connection to the Melbourne supply there would be sufficient

water available to supply Venus Bay and Tarwin Lower in addition to Wonthaggi, Cape Paterson

and Inverloch under the Victoria in Future demand projection. Some additional Melbourne supply

would be required after the year 2040 under the Local Growth scenario. The supply enhancement

shown represents the estimated yield from the combined 10 ML/d Melbourne supply and the Lance

Creek supply system, but with the annual cap on diversion from the Melbourne system increased.

Figure 12-5 Supply from Existing South Gippsland Water Headworks for Wonthaggi, Cape Paterson and Inverloch with supply to unserviced towns near Inverloch

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Connect unservicedtowns in ~2025

Additional supply from Melbourne under Local Growth scenario




October to April, the availability of a large volume in storage and access to the Melbourne and

Powlett River supplies means that South Gippsland Water would be able to maintain supply

through two consecutive years of repeating 2006/07 climate.

12.3. Supply from Melbourne

12.3.1. Supply from Melbourne for Poowong, Loch, Nyora, Korumburra, Leongatha and Koonwarra

As an alternative to the local supply enhancement options for the northern towns, the option of

supplying these towns from Lance Creek Reservoir and/or the Melbourne system was considered.

It is assumed in this option that treated water would be provided to all towns north of Wonthaggi

and that existing raw water supply and treatment plant infrastructure would be decommissioned.

Alternative uses would be sought for raw water storages or they would be decommissioned

The supply and demand projections for this scenario are presented in Figure 12-6. Under the

Victoria in Future growth rates, only Poowong, Loch, Nyora and Korumburra would require

connection to the Melbourne supply. Leongatha would remain as a separate supply system with no

supply augmentations. Under this scenario, supply from the Melbourne system would be sufficient

to meet the demands of these towns over the 50 year planning horizon.

For the Local Growth scenario, it is assumed that Poowong, Loch, Nyora and Korumburra would

again be connected to the Melbourne supply in 2012/13, but that Leongatha would also be

connected to the Melbourne Supply in around 2020. Under these circumstances, the 10 ML/d

Melbourne supply pipeline would be adequate to supply Local Growth demands from all connected

towns to around the year 2029 to 2037, depending on climate conditions. Beyond these dates, the

pipe capacity from the Melbourne supply would need to be upgraded to enable more water to be

harvested from the Melbourne supply under South Gippsland Water‟s existing bulk entitlement.

The Victoria in Future scenario with Murray Goulburn demands only partially realised has not

been presented in the supply and demand projections with connection to the Melbourne system.

This is because when the Melbourne supply augmentation occurs from 2020/21 onwards, the

additional demand from the supply system can readily be catered for with only minor adjustment to

the size of the connection under the Victoria in Future scenario.

Figure 12-6 Supply from Melbourne for Wonthaggi, Cape Paterson and Inverloch plus Poowong, Loch, Nyora, Korumburra, Leongatha and Koonwarra excluding supply to unserviced towns near Inverloch




October to April, the availability of a large volume in storage and access to the Melbourne supply

means that South Gippsland Water would be able to maintain supply through two consecutive years

of repeating 2006/07 climate.

12.3.2. Supply from Melbourne for Poowong, Loch, Nyora, Korumburra, Leongatha and Koonwarra plus unserviced towns near Inverloch

A further supply option would be to supply all northern towns plus Venus Bay and Tarwin Lower

from Lance Creek Reservoir and the Melbourne system. Under the Victoria in Future growth

rates, only Poowong, Loch, Nyora and Korumburra would require connection to the Melbourne

supply. Leongatha would remain as a separate supply system with no supply augmentations. It has

been assumed for the purposes of developing the Water Supply Demand Strategy that demand from

Venus Bay and Lower Tarwin would be supplied, but South Gippsland Water has no defined

timeframes for servicing this demand. Timeframes shown in Figure 12-7 are therefore indicative

only. Under this scenario, supply from the Melbourne system would be sufficient to meet the

demands of the northern, southern and unserviced towns over the 50 year planning horizon under

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Additional supply from Melbourne under Local Growth scenario

Connect Korumburra & PLN in 2012/13

Connect Leongatha in 2020 under Local Growth scenario only

Melbourne supply 10 ML/d- up to +1000 ML/yr 2011/12- up to +2000 ML/yr 2012/13

Additional supply from Melbourne under Local Growth Scenario at 10 ML/d up to +3650 ML/yr total in 2020

medium climate change, with an increase in the annual cap for supply from the Melbourne system

at around 2050. This volume could readily be transferred from the unused Leongatha entitlement

from the Melbourne system.

For the Local Growth scenario, it is assumed that Poowong, Loch, Nyora and Korumburra would

again be connected to the Melbourne supply in 2012/13, but that Leongatha would also be

connected to the Melbourne Supply in around 2020. The unserviced towns are assumed to be

connected around the year 2025. Under these circumstances, the 10 ML/d Melbourne supply

pipeline would be adequate to supply Local Growth demands from all connected towns to around

the year 2025 to 2030, depending on climate conditions and the timing of connection of the

unserviced towns. Beyond these dates, the pipe capacity from the Melbourne supply would need to

be upgraded to enable more water to be harvested from the Melbourne supply under South

Gippsland Water‟s existing bulk entitlement.

Figure 12-7 Supply from Melbourne for Wonthaggi, Cape Paterson and Inverloch plus Poowong, Loch, Nyora, Korumburra, Leongatha and Koonwarra including supply to unserviced towns near Inverloch




October to April, the availability of a large volume in storage and access to the Melbourne supply

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Further increase supply from Melbourne under local growth scenario

Connect unserviced towns in ~2025

Connect Korumburra & PLN in 2012/13

Melbourne supply 10 ML/d- up to +1000 ML/yr 2011/12- up to +2000 ML/yr 2012/13

Connect Leongatha in 2020 underLocal Growth scenario only

Additional supply from Melbourne under Local Growth Scenario at 10 ML/d up to +3650 ML/yr total in 2020

Further increase supply from Melbourne under ViF scenario at 10 ML/d

means that South Gippsland Water would be able to maintain supply through two consecutive years

of repeating 2006/07 climate.

12.4. Sustainability Assessment of Options

The introduction of demand reduction measures in line with other towns supplied by South

Gippsland Water will serve to minimise infrastructure costs and delay the need for supply

augmentations. On a sustainability assessment, demand reduction measures will be preferable to

augmenting the supply system, however in order to meet future demands both actions will be

required.

The sustainability assessment for the northern and southern towns compares the option to supply

from enhancing existing separate headworks and the option to connect the northern and southern

towns to supply from Lance Creek Reservoir and the Melbourne system. The outcome of the

assessment is summarised in Table 12-2 and indicates that the supply from the Melbourne system

has the advantage of being more robust to changes in streamflow under climate change and

potential increases in demand under the Local Growth scenario. A definitive preferred strategy is

dependent on the outcomes of the business case, which is currently being undertaken by South

Gippsland Water. Only preliminary results from the business case were available at the time of

preparing this WSDS. Key points to note about the sustainability assessment are as follows:

There is a higher degree of confidence associated with the Melbourne supply option from a

water resource availability perspective. This is because there is uncertainty in the ability to

maintain supply towards the end of the 50 year planning horizon under the option to supply

from separate headworks. The Melbourne system provides a climate independent source of

water that is more reliable under future climate change and high growth in demand for water.

The second source of uncertainty is the future major industrial demand, which is an area of

uncertainty for both options. If major industrial demand were to decrease then the option to

supply from separate headworks would be more robust, but if major industrial demand were to

increase then the Melbourne supply option would be more robust. The Melbourne supply

option is also considered more resilient to prolonged severe drought.

There is likely to be a net improvement in river health under the Melbourne supply option but

a slight reduction under the option to supply from enhanced separate headworks. This is

because the Melbourne supply option is likely to increase flows in the Little Bass River,

Bellview Creek, Ness Gully, Coalition Creek and Ruby Creek when these supply sources are

decommissioned. The supply from separate headworks would result in greater harvesting of

streamflows from all of the above streams. There would be an increase in water harvesting

from Lance Creek under both options, which would be expected to have a very minor impact

on the health of the Powlett River.

Water quality under the Melbourne supply option would be expected to improve relative to

current conditions whilst water quality under the option to supply from separate headworks

would be expected to marginally decrease. This is because of changes to dilution flow in local

streams in the Bass River and Tarwin River catchments outlined above.

Other ecosystems are unlikely to be significantly affected as a result of either proposal. There

is the possibility of a reduction in marine ecosystem health due to increased use from the

desalination plant under the Melbourne supply option and due to decreased river flows to the

Tarwin River estuary under the option to enhance separate headworks. For both options

vegetation may need to be cleared along proposed pipeline routes if those routes cannot be

located in an existing cleared serviced corridor. For the option to enhance separate headworks,

minor loss of terrestrial habitat would be expected above the current full supply level of the

Little Bass Reservoir, Coalition Creek storages and Ruby Creek storages associated with the

increase in capacity of these storages.

The preliminary cost estimates from the business case indicate that the two supply options

have similar net present costs under both the Victoria in Future and Local Growth scenarios.

These costs may be refined as more detail is included in the business case analysis.

Both options would support more regional development, both through the construction phase

of both options and by providing potable water supply to more customers. The Melbourne

supply option provides greater flexibility to service demands under higher growth and drier

climate change scenarios towards the end of the 50 year planning horizon.

The greenhouse gas emissions are low for both options, but the emissions associated with the

operation of the Melbourne supply option are higher than the supply from separate headworks.

For the Melbourne supply option greenhouse gas emissions for water treatment are lower,

because only one treatment plant is operated at Lance Creek instead of four separate plants,

however power requirements to pump water from Lance Creek to the northern towns are

significantly higher. The supply from the Melbourne system to Lance Creek is carbon neutral.

Increases in greenhouse gas emissions during construction of either option have not been

estimated.

Both options are unlikely to have any impact on recreation and heritage activities in the area.

Both options are likely to be socially acceptable. South Gippsland Water has done some

preliminary consultation and found that stakeholders are amenable to both options, pending the

outcome of the business case. There is some general public opposition to the desalination plant

itself, which in turn could result in some opposition in the short-term to South Gippsland

Water‟s connection to the Melbourne system. Customer complaints could arise when the

supply source is switched due to customer perception of minor differences in taste and/or

odour.

Table 12-2 Sustainability Assessment of Options for Northern and Southern Towns

(1) For broad comparison of options only. See Section 5.1 for further details of the function of this sustainability

assessment within the planning process.

Net

pre

sent

cost

Regio

nal

develo

pm

ent

Gre

enhouse

em

issio

ns

Riv

er

health

Wate

r qualit

y

Oth

er

ecosyste

ms

Culture

, re

cre

ation

and h

erita

ge

Socia

l accepta

bili

ty

Confidence f

lag

LR

MC

($/M

L)

Option: Demand reduction measures

5 1 5 1 0 0 0 3 2 n/a

-5 3 1 -1 -1 -1 0 3 2 tbc

-5 3 2 1 1 -1 0 3 2 tbc

Option: Local supply enhancement

-Increase Little Bass Reservoir by 200 ML

-Increase Korumburra Storages by 200 ML

-Interconnect Little Bass, Coalition Ck and Ruby Ck systems

-Upgrade Tarwin R West Branch Supply to 10 ML/d

-Increase Ruby Ck Storages by 1000 ML

-Source additional water from Melbourne system for unserviced towns

Option: Supply from Melbourne system

-Connect northern and southern towns

-Decommission local raw water storages and treatment plants

-Connect unserviced towns near Inverloch

12.5. Strategy Summary

There is some uncertainty in both the future demand and supply availability for South Gippsland

Water‟s northern and southern towns. South Gippsland Water‟s planning approach is to monitor

demand on an ongoing basis and adjust its plan of action accordingly. South Gippsland Water‟s

monitoring activities in relation to long-term planning for these towns are shown in Figure 12-8.

This monitoring also includes monitoring of asset condition for some of its ageing assets or those in

need of upgrade for other reasons, such as dam safety. In parallel with this monitoring, South

Gippsland Water will complete its planning investigations and preliminary design so that it can

complete its business case of the various supply enhancement options available to better inform its

sustainability assessment. Undertaking these planning investigations and preliminary design will

also prepare South Gippsland Water to implement supply enhancement quickly if changes in

supply or demand occur. The business case is expected to confirm a preferred strategy for South

Gippsland Water, which will then lead into detailed design and planning approvals and finally

commissioning of the new infrastructure. South Gippsland Water will implement its demand

reduction initiatives throughout this process and will continue to consult with its customers on the

outcomes of its ongoing planning activities.

Figure 12-8 South Gippsland Water strategy for South Gippsland Water’s northern and southern towns and unserviced towns near Inverloch

Whilst the course of action required will vary according to the outcomes of the business case and

future monitoring of supply and demand, the approximate timing of infrastructure augmentations

Finalise planning investigations and preliminary design

Monitor change in consumption:-Bulk meter consumption (annually)-Major industrial consumption (annually)-Census population (2011 results available in 2012)-Victoria in Future population projections (~2013)-Major industrial demand growth projections (annually)

Prepare business case with final sustainability assessment including financial modellingMonitor other needs for infrastructure upgrades:

-Water quality treatment plant end of life e.g. Leongatha Treatment Plant around 2020-Dam safety upgradese.g. Bellview Creek Reservoir around 2018-20

Detailed design and planning approvals

Augment infrastructure

De

man

d r

ed

uct

ion

init

iati

ves

Monitoring Planning and investigations

Cu

sto

me

r co

nsu

ltat

ion

under the two growth scenarios is shown in Figure 12-9. This figure highlights that South

Gippsland Water is expecting to implement augmentation options quickly after finalising the

business case. Other actions will be timed to align with dam safety and treatment plant upgrades

where practicable. As mentioned previously, the timing of these actions is subject to change as

more information is collected by South Gippsland Water. It can be seen from Figure 12-9 that the

supply from existing separate South Gippsland Water headworks still requires connection to the

Melbourne system from 2025 onwards if demands follow the Local Growth trajectory.

Figure 12-9 Approximate timing of South Gippsland Water infrastructure augmentation

Immediate and ongoing actions which are applicable to both options are listed in Table 12-3.

These include actions to monitor demands.



Approx. Timing












Approx. Timing









Table 12-3 Actions for towns east of the Tarwin River and unserviced towns near Inverloch

Strategy Actions

Reduce uncertainty in current

estimate of consumer demand

- Compare quarterly or four monthly consumption data from property

and bulk meters

Reduce uncertainty in future


- Examine long-term trends in bulk water use independent of climate

variability.

- Continue monitoring Burra Foods demand and request an annual

update on longer term water demand forecasts

- Continue tracking Murray Goulburn and steam plant demand and

request an annual update on its progress to achieve water savings

- Proceed with planning investigations and design to supply unserviced

towns near Inverloch

Encourage demand reduction - Pursue additional demand reduction options after adoption by

WaterSmart

- Continue ongoing program of system leak reduction and inspections

for unmetered tappings

13. Supply and Demand Projections for Dumbalk with Current Operation and Infrastructure

13.1. Introduction

This section of the WSDS outlines the supply and demand projections for Dumbalk over the next

50 years assuming current operation and infrastructure. It includes an overview of the current





towns.



Dumbalk receives water directly from the east branch of the Tarwin River via a pump station which

is located adjacent to the river. The pump station transfers water to the water treatment plant via a

150 mm diameter rising main. The capacity of the pumped diversion is 0.7 ML/d (21.3 ML/mth).

The water treatment plant has a capacity of 0.4 ML/d (12.2 ML/mth). A schematic of the Dumbalk

water supply system is shown in Figure 13-1.

Figure 13-1 Tarwin East Water supply system schematic


The bulk entitlement for Dumbalk allows South Gippsland Water to divert up to a maximum of

100 ML/yr from the Tarwin River. The daily bulk entitlement is shown in Table 13-1.

Table 13-1 Bulk entitlement volume for the Tarwin River at Dumbalk

Source Maximum

annual volume

Maximum diversion

rate Minimum passing flows

Tarwin River at Dumbalk 100 ML/yr 0.72 ML/d

(21.9 ML/mth) No minimum passing flows


Dumbalk had a population of 155 people excluding visitors in the 2006 census (DPCD, 2009). A



climate variability. The historical and estimate long-term current demand is shown in Figure 13-2.

The estimate long-term current demand is 17 ML/yr at South Gippsland Water‟s treatment plant

inlet. There are no net losses across the treatment plant. Figure 13-2 shows that the long-term

current demand is much lower than that which occurred historically and has been sustained for the

last two years.

Dumbalk Water Supply System Area Supervisor

Date Issued

Revision No.


02/07/2004

1.0

Not yet

Brian Ashworth

POPULATION:

Estimated 160

Town is not seweredTarwin River

(East branch)

sodium

hypochlorite

water

tower

bore

(emergency)

STORAGES:

Water tower (concrete, roofed, 227 kL)

Clear water storage - concrete roofed, 0.1 ML

pump station

DUMBALK

treatment

plant

low level clear

water storage

cap 0.7 ML/d

SOURCE:

Tarwin River (east branch)

Bore (emergency only, ie drought)

Full treatment with poly aluminium chlorite, soda ash,

polyelectrolyte, sodium hypochlorite

TREATMENT:

Flocculation, Clarification, Filtration, Chlorination

Figure 13-2 Long-term monthly demands for Dumbalk


Restrictions were introduced at Dumbalk from January to June 2007, which included several

months of Stage 4 restrictions. Restrictions have not historically been required at any other time

over the last 15 years. Since 2006/07 the supply and demand balance has been improved through a

reduction in demand. Reliability of supply modelling over the period July 1950 to June 2007

indicated that restrictions would not have been required over that period under a repeat of historical

climate conditions. This meets South Gippsland Water‟s level of service objective for restrictions.

It should be noted however that it has been reported that in the 1967/68 and 1982/83 droughts there

was a need to sandbag the Tarwin River East branch to secure supply for the town. Further details


(2009).


Dumbalk is located on the Tarwin River East Branch. Dumbalk currently extracts a negligible

proportion of the available flow in the Tarwin River, even during low flow conditions and therefore

has little influence on environmental condition. The Tarwin River East Branch flows from the

Strzlecki Ranges in the north and east, flowing downstream to join the West Branch at Meeniyan.

The river then flows into Andersons Inlet at Tarwin Lower. There are a few small undefined

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tributaries and drainage lines from low lying swamps that enter the river in the reaches below

Meeniyan. The main tributary is Fish Creek which flows into the Tarwin River from the east a few

kilometres upstream of Tarwin Lower.

Information about the environmental condition of Tarwin River West Branch and the Tarwin River

downstream of the confluence of the East and West Branches was assessed for South Gippsland

Water in SKM (2006b) Tarwin River Preliminarily Environment Assessment. The outcomes of that

assessment, primarily for the Tarwin River below its confluence of the East and West Branches, are

discussed below.









populations of Australian grayling in the Tarwin River immediately below the offtake at Meeniyan.






Installation of a fish ladder at the offtake at Meeniyan has been identified as a priority by DSE

(Justin O‟Connor, pers. com.).

Clearing for agriculture and willow plantings have impacted on the structure and condition of

riparian vegetation along the Tarwin River East Branch. In general, ISC assessments record the

streamside zone and physical form of the river as poor. Tarwin River East Branch has a degraded

riparian zone with little native vegetation. There are some bank instabilities that extend to the toe of

the bank. The catchment is moderately flow stressed with greater stress in summer than in winter.

Aquatic life ratings were excellent. In the basin downstream, artificial barriers are likely to affect

migration of fish species. The degraded condition of the instream habitat and the riparian zone in

the mid and lower parts of the catchment must be seen as a significant threat to the native fish

community within the Tarwin River.

The above assessments were confirmed in the environmental flow assessment for the Tarwin River

East Branch in SKM (2009). The environmental flow assessment linked the provision of low flows

to maintaining habitat in pools for river blackfish, to maintain habitat, to allow fish movement, and

to provide moisture for riparian and fringing plants. Summer freshes were important for preventing

colonization of riparian areas by terrestrial plants, to entrain organic matter and transport nutrients

downstream, whilst slightly higher, short duration transitional flows in summer were considered

important for triggering fish migration. Winter low flows were designed to maintain habitat,

provide water for reeds and rushes, and prevent colonisation of weeds, while high flow freshes


juvenile fish species, including Australian Grayling and Galaxiids. Bankfull flows were

recommended to maintain channel forming processes and no overbank flows were specifically

recommended.



Historical demands to Dumbalk have decreased significantly over the last few years, as shown in

Figure 13-3. These demands are recorded at the clear water storage outlet and do not include an

allowance for treatment plant utilisation. The number of customers billed in this supply system has

remained relatively static. This potentially indicates that significant water savings have been

achieved by South Gippsland Water and its customers in recent years.

Figure 13-3 Historical demands and number of customers billed at Dumbalk

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The population of Dumbalk has fluctuated between approximately 140-190 people over the last

few decades and there are no clear trends in the long-term, as shown in Figure 13-4. The number

of dwellings has increased marginally in recent years.

Figure 13-4 Historical population in Dumbalk






covering South Gippsland Water‟s supply area. Dumbalk is located within the South Gippsland

Shire East SLA and accounts for around 3% of the population within that SLA, hence SLA

projections are only likely to be broadly representative of growth at Dumbalk.




closer to the growth which actually happened, which was no change in population at Dumbalk.

Given the uncertainty of future population, South Gippsland Water has considered two population

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1981 1986 1991 1996 2001 2006

Po

pu

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Dwellings - Dumbalk

Population - Dumbalk



Victoria in Future projections include a growth in residential demand of up to 0.3% per year over

the next few years and then falling to no growth by around 2035. The Local Growth scenario

assumes a 0.7% annual growth rate in residential demand over the fifty year planning horizon.




hotter climate change conditions, which is consistent with DSE recommendations (DSE, 2005).






evaporation. Under the ongoing low flow conditions scenario, Tarwin River sub-catchment

streamflows upstream of Dumbalk have been reduced by 34-41% prior to July 1997.

The Current Operation and Infrastructure water supply and demand situation for the Dumbalk


figure illustrates that demand is not expected to exceed available supply in the foreseeable future.

Figure 13-5 Current Operation and Infrastructure Water Supply and Demand for Dumbalk


Three potential land use changes within the catchment supplying Dumbalk were investigated to


Bushfires: Only 31% of the Tarwin River catchment upstream of Dumbalk has vegetation cover.

This means that the risk of catchment yield decreasing significantly due to the effects of any future

bushfires is low. There is no record of bushfires occurring in the catchment over the last few

decades.





If the additional demand reduction options outlined in Section 4.10 are adopted for Dumbalk,

demands would remain below the available supply, as shown in Figure 13-6.

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Yield under medium climate change and ongoing low flow conditions

Figure 13-6 Effect of additional demand reduction options for Dumbalk

13.7. Summary of the supply and demand for Dumbalk with current operation and infrastructure

In summary for Dumbalk under the Current Operation and Infrastructure supply and demand

scenarios:

Existing supply is sufficient to meet South Gippsland Water‟s current level of service

objectives over the 50 year planning horizon;

Demand for water has fallen in recent years and population has slightly increased ; and


planning horizon.

A summary of South Gippsland Water‟s strategy for Dumbalk in the context of South Gippsland

Water‟s strategy for the central towns is presented in Section 19.

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Local growth demnd under medium climate change with future demand reduction measures


14. Supply and Demand Projections for Meeniyan with Current Operation and Infrastructure

14.1. Introduction

This section of the WSDS outlines the supply and demand projections for Meeniyan over the next






towns.



Meeniyan‟s water supply is taken directly from the Tarwin River at Meeniyan (downstream of

227202). A pump station located adjacent to the river transfers water via a 150 mm diameter pipe

to a small water storage basin (5.5 ML) located south of the town centre. A schematic of the

Meeniyan water supply system is shown in Figure 14-1.

Figure 14-1 Tarwin River Water Supply System Schematic


The bulk entitlement for Meeniyan allows South Gippsland Water to divert up to a maximum of

200 ML/yr from the Tarwin River. The daily bulk entitlement is shown in Table 14-1. A

qualification of rights to this entitlement was granted in 2008, which allowed up to 1800 ML/yr to

be diverted from Gwyther‟s Siding Road to supply Leongatha and Korumburra. This qualification

of rights is being formalised into an amendment to the entitlements for Leongatha and Korumburra

and is discussed in the sections of this WSDS for those supply systems.

Table 14-1 Bulk entitlement volume for the Tarwin River at Meeniyan (South Gippsland Water, 2007)

Source Maximum annual

volume

Maximum

diversion rate Minimum passing flows

Tarwin River at Meeniyan 200 ML/yr 1.3 ML/d



Meeniyan had a population of 413 people excluding visitors in the 2006 census (DPCD, 2009). A

demand model was fitted to recent unrestricted data to estimate long-term average annual demand,

SOURCE: Tarwin River

Tarwin

River

STORAGES: Service basin No. 1 - earthen, open, 5.9 ML

water tower - steel, covered, 480 kL

pump station

MEENIYAN

treatment

plant

12 rural users

service basin

cap 1.3 ML/d pump water

tower

sodium

hypochlorite

POPULATION: Estimated 420 - Town is not sewered

TREATMENT: Full treatment with poly aluminium chloride, soda

ash, poly electrolyte coagulation, sedimentation, filtration &

chlorination (sodium hypochlorite)

Meeniyan Water Supply System Area Supervisor

Date Issued

Revision No.


02/07/2004

1.0

Not yet

Brian Ashworth

which takes into account how current demands would vary under a wider range of natural climate

variability. The historical and estimated long-term current demand is shown in Figure 14-2. The

long-term average annual demand is 65 ML/yr at South Gippsland Water‟s treatment plant inlet, of

which around 3% is utilised on average through the treatment plant. Historical demand has

remained relatively static since 2004/05.

Figure 14-2 Long-term monthly demands for Meeniyan


Restrictions were introduced at Meeniyan from January to June 2007, which included several

months of Stage 4 restrictions. Restrictions have not historically been required at any other time

over the last 15 years. Since 2006/07 the supply and demand balance has been improved through a

sustained reduction in demand. Reliability of supply modelling over the period July 1950 to June

2007 indicated that restrictions would not have been required over that period under a repeat of

historical climate conditions. This meets South Gippsland Water‟s level of service objective for

restrictions. Further details on the water resource model used to assess reliability of supply (and

yield) can be found in SKM (2009).

0

2

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8

10

12

14

16


De

man

d t

o T

reat

me

nt

Pla

nt

(ML/

mo

nth

)

Historic

EstimatedRestrictions

Demand Model Calibration Period

(restrictions excluded)


Meeniyan is located on the Tarwin River just below the confluence of the East and West Branches.

Meeniyan currently extracts a negligible proportion of the available flow in the Tarwin River, even

during low flow conditions and therefore has little influence on flow volumes in the river. The

Tarwin River flows from the Strzlecki Ranges in the north to Andersons Inlet at Tarwin Lower.

There are a few small undefined tributaries and drainage lines from low lying swamps that enter the

river in the reaches below Meeniyan. The main tributary is Fish Creek which flows into the Tarwin

River from the east a few kilometres upstream of Tarwin Lower.

Information about the environmental condition of Tarwin River downstream of the confluence of

the East and West Branches was assessed for South Gippsland Water in SKM (2006b) Tarwin

River Preliminarily Environment Assessment. The main relevant outcomes of that assessment are

discussed below.









populations of Australian grayling in the Tarwin River immediately below the offtake at Meeniyan.






Installation of a fish ladder at the offtake at Meeniyan has been identified as a priority by DSE

(Justin O‟Connor, pers. com.).

Water quality and Index of Stream Condition were generally found to be poor along the Tarwin

River.

The above assessment was confirmed in the environmental flow assessment for the Tarwin River in


habitat in pools for river blackfish, to maintain habitat, to allow fish movement, and to provide

moisture for riparian and fringing plants. Summer freshes were important for preventing


downstream, whilst slightly higher, short duration transitional flows in summer were considered

important for triggering fish migration. Winter low flows were designed to maintain habitat and

prevent colonisation of weeds, while high flow freshes were intended to maintain channel forming

processes and to facilitate the upstream migration of Tupong and juvenile fish species, including

Tupong, Australian Grayling and Galaxiids. Bankfull flows were recommended to maintain

channel forming processes and no overbank flows were specifically recommended.



Historical demands for Meeniyan have decreased steadily over the last few years, as shown in

Figure 14-3. These demands are recorded at the clear water storage outlet and do not include an

allowance for treatment plant utilisation. The number of customers billed in this supply system has

increased marginally. This potentially indicates that significant water savings have been achieved

by South Gippsland Water and its customers in recent years.

Figure 14-3 Historical demands and number of customers billed at Meeniyan

The population of Dumbalk has fluctuated between approximately 360-420 people over the last

few decades and there are no clear trends in the long-term, as shown in Figure 14-4. The number

of dwellings has increased marginally in recent years.

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Figure 14-4 Historical population in Meeniyan






covering South Gippsland Water‟s supply area. Meeniyan is located within the South Gippsland

Shire Central SLA and accounts for around 3% of the population within that SLA, hence SLA

projections are only likely to be broadly representative of growth at Meeniyan.


from the 2001 census indicated that both the Victoria in Future and the Local Growth projections

underestimated population growth between 2001 and 2006. However the change in population of

10% that occurred at Meeniyan over this period is within the natural variability observed between

previous censuses over the last two decades and does not necessarily represent a departure from

historically low growth rates. Small fluctuations in population can appear large in percentage

terms for this small town. Given the uncertainty of future population, South Gippsland Water has

considered two population forecasts, which include the Victoria in Future projections and a higher

Local Growth scenario that allows for faster growth in urban centres within SLAs.

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Population - Meeniyan

Victoria in Future projections include a growth in residential demand of 0.4-0.9% per year with

growth rates peaking at around the year 2016. The Local Growth scenario assumes a 1.5% annual

growth rate in residential demand over the fifty year planning horizon.










evaporation. Under the ongoing low flow conditions scenario, Tarwin River sub-catchment

streamflows upstream of Meeniyan have been reduced by 34-52% prior to July 1997.

The Current Operation and Infrastructure water supply and demand situation for the Meeniyan


figure illustrates that demand is not expected to exceed available supply in the foreseeable future.

Figure 14-5 Current Operation and Infrastructure Water Supply and Demand for Meeniyan


Three potential land use changes within the catchment supplying Meeniyan were investigated to


Bushfires: Only 18% of the Tarwin River catchment upstream of Meeniyan has vegetation cover.

This means that the risk of catchment yield decreasing significantly due to the effects of future

bushfires is low. There is no record of bushfires occurring in the catchment over the last few

decades.





If the additional demand reduction options outlined in Section 4.10 are adopted for Meeniyan,

demands would remain below the available supply, as shown in Figure 14-6.

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Figure 14-6 Effect of additional demand reduction options for Meeniyan

14.7. Summary of the supply and demand for Meeniyan with current operation and infrastructure

In summary for Meeniyan under the Current Operation and Infrastructure supply and demand

scenarios:



Demand for water has fallen in recent years, population has remained static and the number of

dwellings has increased; and


planning horizon.

A summary of South Gippsland Water‟s strategy for Meeniyan in the context of South Gippsland


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15. Supply and Demand Projections for Foster with Current Operation and Infrastructure

15.1. Introduction

This section of the WSDS outlines the supply and demand projections for Foster over the next 50

years assuming current operation and infrastructure. It includes an overview of the current supply

system configuration, current demand for water and current supply. It also includes supply and

demand projections under future climate change and alternative growth scenarios over the 50 year

planning horizon. South Gippsland Water‟s response to any shortfall in demand under the current

operation and infrastructure scenarios is presented in Section 19 in conjunction with nearby towns.



The Foster Water Supply System is comprised of an on-stream weir (total storage capacity =

19 ML, dead storage = 5 ML) located on Deep Creek and an off-stream storage constructed in 1997

(Foster Dam 233 ML, dead storage = 10 ML). Water is diverted from Deep Creek Reservoir all

year round to Foster Dam storage through a gravity pipeline of 3.5 ML/d capacity. When the on-

stream storage stops spilling there is no transfer of water to Foster Dam or the treatment plant via

the supply pipeline, although it continues to supply raw water to 12 rural customers. From Foster

Dam, the water is pumped to the treatment plant raw water basin. The pump and pipeline capacity

from the basin to Foster is 2.6 ML/d. Figure 15-1 shows a schematic representation of the supply

system.

Figure 15-1 Deep Creek Water Supply System Schematic


The bulk entitlement for Foster allows South Gippsland Water to divert up to a maximum of

326 ML/yr from Deep Creek. The daily bulk entitlement is shown in Table 15-1.

Table 15-1 Bulk entitlement volume for Foster

Source Maximum

annual volume

(ML/yr)

Maximum

diversion rate

(ML/d)


Deep Creek 326 3.5 Minimum of 0.2 ML/d or natural flow


Foster had a population of 947 people in the 2006 census excluding visitors (DPCD, 2009). A

demand model was fitted to recent unrestricted data to estimate long-term average annual demand,

which takes into account how current demands would vary under a wider range of natural climate

variability. The historical and estimated long-term current demand is shown in Figure 15-2. The

estimated long-term average annual demand is 140 ML/yr at South Gippsland Water‟s treatment

plant inlet, of which around 7% is utilised on average through the treatment plant.

Figure 15-2 Long-term monthly demands for Foster


There have been no recent water restrictions in Foster and the supply system currently meets level

of service objectives. Reliability of supply modelling over the period July 1963 to June 2007

indicated no restrictions would have been required at current demands over this historical climate

period. The minimum storage reached in this scenario was estimated to be 95 ML. Further details


(2009).


Deep Creek is a tributary of the Franklin River. No environmental condition assessment has been

undertaken for Deep Creek. There are no Index of Stream Condition sites on Deep Creek, although

the Index of Stream Condition for the lower Franklin River was assessed as moderate.

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Historical demand at Foster declined sharply in the year 2000/01 and has steadily declined further

over the last two years, as can be seen in Figure 10-3. These diversions are recorded at the clear

water storage outlet and do not include an allowance for treatment plant utilisation. The number of

customers billed in this supply system has increased in this supply system over the last few years,

as shown in Figure 15-3. This potentially indicates that significant water savings have been

achieved by South Gippsland Water and its customers in recent years.

Figure 15-3 Historical demand and number of customers billed at Foster

The population of Foster has declined slightly over the last two decades, as shown in Figure 15-4,

with the total population decreasing from 1,030 in 1991 to 947 in 2006. Between 2001 and 2006

the population remained static whilst the number of dwellings increased slightly.

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Figure 15-4 Historical population in Foster





higher growth within towns at a rate greater than the surrounding SLA. There are five SLAs

covering South Gippsland Water‟s supply area. Foster is located within the South Gippsland Shire

East SLA and accounts for around 16% of the population within that SLA.



overestimated SLA population growth between 2001 and 2006. The Victoria in Future projections

were closer to the growth which actually happened, which was no change in population. However,

given the uncertainty of future population, South Gippsland Water has considered two population



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evaporation. Under the ongoing low flow conditions scenario, Deep Creek streamflows upstream

of Deep Creek Reservoir have been reduced by 43% prior to July 1997.

The Current Operation and Infrastructure water supply and demand situation for the Deep Creek


figure illustrates that demand is not expected to exceed available supply for the foreseeable future.

Figure 15-5 Current Operation and Infrastructure Water Supply and Demand for Foster

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Three potential land use changes within the catchment supplying Foster were investigated to


Bushfires: The maximum reduction in runoff after a bushfire typically occurs at around

10-20 years after the fire has occurred, and thereafter runoff progressively increases back to pre-

bushfire levels. Approximately 55% of the Deep Creek catchment upstream of Foster has

vegetation cover, however there is no record of recent bushfires occurring in the South Gippsland

region. The effects of bushfire on catchment yield will therefore only be a concern if fires occur in

this area in the future.





If the additional demand reduction options outlined in Section 4.10 are adopted for Foster, demands

would remain below the available supply, as shown in Figure 15-6.

Figure 15-6 Effect of additional demand reduction options for Foster

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15.7. Summary of the supply and demand for Foster with current operation and infrastructure

In summary for Foster under the Current Operation and Infrastructure supply and demand

scenarios:



Demand for water has fallen in recent years, population has remained static and the number of

dwellings has increased; and


planning horizon.

A summary of South Gippsland Water‟s strategy for Foster in the context of South Gippsland


16. Supply and Demand Projections for Fish Creek with Current Operation and Infrastructure

16.1. Introduction

This section of the WSDS outlines the supply and demand projections for Fish Creek over the next






towns.



The township of Fish Creek and the surrounding rural areas are supplied from a 119 ML reservoir

(live storage = 123 ML and dead storage = 4 ML) located on Battery Creek. The water is

transferred from the storage to a treatment plant of 2 ML/day (60.8 ML/mth) capacity through a

pipeline of 1.7 ML/day (51.7 ML/mth) capacity, into a 1.1 ML lined and covered basin. The water

is then supplied directly to the town via the mains pipes, and the rural demands are supplied via the

same system. A schematic of the supply system is shown in Figure 16-1.

Figure 16-1 Battery Creek Water Supply System Schematic


The bulk entitlement for Fish Creek allows South Gippsland Water to divert up to a maximum of

251 ML/yr from Battery Creek. The daily bulk entitlement is shown in Table 16-1.

Table 16-1 Bulk entitlement volume for Fish Creek

Source

Maximum

annual

volume

Maximum

diversion rate Minimum passing flows

Battery Creek 251 1.0 ML/d



Fish Creek had a population of 144 people excluding visitors in the 2006 census (DPCD, 2009). A



climate variability. The historical and estimated long-term current demand is shown in Figure

16-2. The long-term average annual demand is 140 ML/yr at South Gippsland Water‟s treatment

Battery Creek

Reservoir

treatment

plant

FISH CREEK

STORAGES: Battery Creek

Reservoir - earthen, open, 118

ML Service Basin - concrete,

covered & lined, 1.1 ML

2 No. elevated Storage Tanks -

concrete, roofed, 90 kL ea.

SOURCE: Battery Creek

to rural farmsto rural farms

Falls RdCornwalls Rd

booster pump

station

Battery Creek

springs

gravity

to rural farms

sodium

hypochlorite

cap 1.7

ML/d

service

basin

RL 88.5

clear water

storage tanks

RL 117.0aeration

(future)

pump

sodium

hypochlorite

to west branch

rural farms

POPULATION: Estimated 200 (plus 90

rural connections). Town is not sewered.

TREATMENT: potassium permanganate, alum, soda

ash, sodium hypochlorite coagulation, filtration,

chlorination

Fish Creek Water Supply System Area Supervisor

Date Issued

Revision No.


02/07/2004

1.0

Not yet

Brian Ashworth

123

plant inlet, of which around 7% is utilised on average through the treatment plant. Note that this

level of demand is significantly lower than historical water use, which is discussed further in

Section 16.4.1 and is allowed for as part of the sensitivity analysis for Fish Creek in Section 16.5

and in the strategy for the central towns in Section 19.

Figure 16-2 Long-term monthly demands for Fish Creek


Fish Creek has historically experienced restrictions on average every second year over the last

decade. This included severe restrictions (Stage 4 of 4 stages or equivalent) in 1999/2000,

2000/01, 2002/03, 2006/07 and 2007/08. Reliability of supply modelling over the period July 1950

to June 2007 indicated that restrictions would have been required on 4 occasions at current

demands over this historical climate period. This corresponds to an annual reliability of supply of

93%, which meets South Gippsland Water‟s level of service objectives. The minimum storage

reached was estimated to be 23 ML. Annual reliability of supply is estimated to be higher than that

which has occurred historically and in the previous WSDS because of a reduction in current

demand and a revision to restriction triggers. Further details on the water resource model used to

assess reliability of supply (and yield) can be found in SKM (2009).

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Fish Creek is the main tributary that flows into the lower Tarwin River. Hoddle Creek and Battery

Creek are tributaries of Fish Creek and it can be assumed that the health of Fish Creek partially

reflects the health of Hoddle Creek and Battery Creek.

Water quality data provided for Fish Creek in WGCMA (2006), showed water quality was poor

with low dissolved oxygen, high pH, EC and turbidity and orthophosphate (phosphorus)

concentrations. SIGNAL scores for macroinvertebrates indicate mild pollution was probably

occurring. In addition, there was greater than 80% of aquatic weeds and algae present which

indicates high concentrations of nutrients in the river at this site. Results from the two ISC sites

along Fish Creek indicated that the creek was degraded and stressed with lower flows occurring in

summer. The banks were degraded with limited vegetation and some erosion occurring. Both ISC

sites rate Fish Creek as Poor (VWQDW, 2007).

There were no ISC sites located on Battery and Hoddle Creeks and there is limited information is

available on the ecology of these streams. Consequently, is difficult to assess the impact of

changes in flow on the condition of these creeks.

The above assessments were confirmed in the environmental flow assessment for Fish Creek in


habitat in pools for river blackfish, to maintain habitat, to allow fish movement, and to provide

moisture for riparian and fringing plants. Summer freshes were important for preventing


downstream. Winter low flows were designed to maintain habitat and prevent colonisation of

weeds, while high flow freshes were intended to maintain channel forming processes and to

facilitate the upstream migration of juvenile fish species. Bankfull flows were recommended to

maintain channel forming processes and to water swamp paperbarks. An overbank flow was

recommended to provide connectivity to wetlands and support flood dependent taxa.



Historical demands at Fish Creek have declined significantly in the last four years, as can be seen

in Figure 16-3. These diversions are recorded at the clear water storage outlet and do not include

an allowance for treatment plant losses. Restrictions have affected demand over some of the recent

period, however in 2008/09 restrictions were not in place and demand remained low.

The main reason for the reduction in demand is South Gippsland Water‟s WaterMap initiative,

which offered interest free loans to rural customers to reduce their reliance on South Gippsland

Water‟s water supply infrastructure. This program has reduced the rural water use from the system

significantly in recent years.

Figure 16-3 Historical diversions and number of customers billed at Fish Creek

The population of Fish Creek has declined significantly over the last decade, as shown in Figure

16-4, with the total population decreasing from 182 in 1991 to 144 in 2006. The number of

dwellings has remained relatively constant over that period.

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Figure 16-4 Historical population in Fish Creek






covering South Gippsland Water‟s supply area. Fish Creek is located within the South Gippsland

Shire East SLA and accounts for around 2% of the population within that SLA.




closer to the growth which actually happened, which was a decline in population by 3%. However,




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assumes a 0.7% annual growth rate in residential demand over the fifty year planning horizon. The

Local Growth Scenario also includes an allowance for a potential increase in demand of 50 ML/yr

from rural customers. This scenario assumes that rural customers could need to supplement their

on-farm supplies in a drought year, which would see their demand for supply from South

Gippsland Water return to a level similar to that seen prior to the implementation of the WaterMap

initiative.










evaporation. Under the ongoing low flow conditions scenario, Battery Creek streamflows upstream

of Battery Creek Reservoir have been reduced by 41% prior to July 1997.

The Current Operation and Infrastructure water supply and demand situation for the Battery Creek


figure illustrates that demand exceeds available supply at South Gippsland Water‟s level of service

objective under the ongoing low flow scenario and is expected to exceed supply by around 2024

under the medium climate change scenario if no further action is taken and growth in demand for

water occurs in accordance with population projections.

Figure 16-5 Current Operation and Infrastructure Water Supply and Demand for Fish Creek


Three potential land use changes within the catchment supplying Fish Creek were investigated to

understand the potential risk they could pose to available supply. Additional information on

potential future growth in demand for rural customers, who are a significant component of this

supply system, is also presented.

Bushfires: Only 27% of the Battery Creek catchment has vegetation cover. This means that the

risk of catchment yield decreasing significantly due to the effects of bushfires is low. There is no





Growth in water demand: CEE (2006) held discussions with individual landholders to investigate

rural water use. The range of water used on individual farms is shown in Figure 16-6. In the farms

with high water use, water is used for washing out dairies, cleaning milk equipment, drinking water

for stock and supplying residences on the farms. The farms using little water are generally only

supplying the farmhouse. Discussions with two large farm water users revealed that:

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Local Growth demand under medium climate change



Dairy herd sizes were slowly increasing with time, but water use was not expected to increase

much in the future;

Farmers were conscious of the need to conserve water - for example, water was used to cool

and clean equipment and then reused to wash the dairy area;

Yard wash water was collected in a dam and used to irrigate the adjacent land;

Farmers complied with water restrictions at their households but were not able to reduce water

use by cows or in their dairy (this is consistent with the State policy that water restrictions do

not apply to industry or where there may be a public health impact);

Farm size was slowly increasing and hence there would be fewer farms in the future;

Some productive farms were being converted to hobby farms or grazing properties;

Leaks were a significant cause of occasional high water use (up to 1 ML per leak) and were

difficult to detect in wet seasons;

Farmers were sensitive to the cost of water; and

Water demand by farmers is likely to stay much the same as at present.

The reductions in rural water use associated with South Gippsland Water‟s WaterMap initiative

have been sustained since the 2006/07 drought. These rural water users are however still connected

to the South Gippsland Water supply system and it is possible that they may draw upon South

Gippsland Water‟s supply system in a severe drought to complement their on-farm water supplies.

If this were to occur, then demand from the system in a very dry year could return to above 200

ML/yr. This risk is considered as part of the strategy for South Gippsland Water‟s central towns,

presented subsequently in Section 19.

Figure 16-6 Water use by farmers in Fish Creek (from CEE, 2006)

When considering household water use in the town, CEE (2006) concluded that there was scope for

demand to increase in the majority of households as properties currently held by elderly singles or

couples were passed on to younger families.


If the additional demand reduction options outlined in Section 4.10 are adopted for Fish Creek, the

time to augmentation under the medium climate change scenario would be extended slightly, as

shown in Figure 16-7.

Fish Creek

Water Use by Farmers

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1 3 5 7 9 11 13 15 17 19 21 23 25 27 29 31 33 35 37 39 41 43 45 47 49 51 53

Farm Customer

Wate

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Average use = 2.7 ML/year/property

Total use = 145.7 ML/year

Figure 16-7 Effect of additional demand reduction options for Fish Creek

16.7. Summary of the supply and demand for Fish Creek with current operation and infrastructure

In summary for Fish Creek under the Current Operation and Infrastructure supply and demand

scenarios:


objectives under medium climate change and is just below those service objectives under a


Under the medium climate change scenario, demand for water is expected to exceed available

supply by around 2029;

Demand for water has fallen in recent years, primarily due to a reduction in rural water use

associated with South Gippsland Water‟s WaterMap program. These rural users are still

connected to the supply system and could temporarily increase demand from South Gippsland

Water‟s supply system in a severe drought; and



A summary of South Gippsland Water‟s strategy for Fish Creek in the context of South Gippsland


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Local growth demnd under medium climate change




17. Supply and Demand Projections for Toora, Welshpool, Port Welshpool and Port Franklin with Current Operation and Infrastructure

17.1. Introduction

This section of the WSDS outlines the supply and demand projections for Toora, Welshpool, Port

Welshpool and Port Franklin over the next 50 years assuming current operation and infrastructure.

It includes an overview of the current supply system configuration, current demand for water and

current supply. It also includes supply and demand projections under future climate change and

alternative growth scenarios over the 50 year planning horizon. South Gippsland Water‟s response

to any shortfall in demand under the current operation and infrastructure scenarios is presented in

Section 19 in conjunction with nearby towns.



The Agnes River water supply system consists of a 58.7 ML storage at Cooks Dam on the Agnes

River, with a diversion weir located 2 km downstream of the storage. Cooks Dam is used to

provide additional security to the system when the flows are low in dry periods. From the diversion

weir a 4.8 ML/day pipeline supplies water to the treatment plant which then transfers water to a

30 ML off-stream balancing storage. Water is then distributed to customers. A schematic is shown

of the system in Figure 17-1.

Figure 17-1 Agnes River Water Supply System Schematic


The bulk entitlement for Toora allows South Gippsland Water to divert up to a maximum of

1,617 ML/yr from the Agnes River. The daily bulk entitlement is shown in Table 17-1.

Table 17-1 Bulk entitlement volume for Toora

Source Maximum annual

volume (ML/yr)

Maximum diversion

rate (ML/d)


Agnes River 1617 4.8 Minimum of 1.0 ML/d or natural flow


Toora, Welshpool, Port Welshpool and Port Franklin had populations of 454, 146, 172 and 115

people respectively in the 2006 census excluding visitors (DPCD, 2009). This corresponds to a

total of 887 people for the four towns. A demand model was fitted to the recent unrestricted data to

estimate a long-term average annual demand, which takes into account how current demands would

vary under a wider range of natural climate variability. The historical and estimated long-term

current demand is shown in Figure 17-2. Data prior to July 2006 was subject to meter errors and

was not used in the estimation of current demands. The long-term average annual demand is

564 ML/yr at South Gippsland Water‟s treatment plant inlet meter, of which around 10% is

utilised on average through the treatment plant.

Figure 17-2 Long-term monthly demands for Toora, Welshpool, Port Welshpool and Port Franklin


Restrictions have historically been very infrequent in this supply system, however they have

increased in recent years. From 1996 to 2009, Stage 6 (of 8 stages) restrictions occurred for a

period of two weeks in March 2001, whilst Stage 2 and then Stage 4 (of 4 stages) restrictions were

introduced from January to June 2007. Since 2006/07 the supply and demand balance has been

improved slightly through the development of revised restriction triggers and a reduction in

demand. Reliability of supply modelling over the period July 1950 to June 2007 indicated that

restrictions would have been required only once over this period when using the current set of

restriction triggers at the current level of demand. This corresponds to an annual reliability of

supply of 98%, which meets South Gippsland Water‟s level of service objective. The minimum

storage reached was 7 ML. Further details on the water resource model used to assess reliability of

supply (and yield) can be found in SKM (2009).

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The Agnes River is a perennial stream that rises on the southern slopes of the Strzlecki Ranges in

South Gippsland. The headwaters of the stream are within the Strzlecki State Park, but

downstream of the park, sections of the upper catchment are under plantation and some areas have

been cleared for agriculture (mainly grazing and dairy). The middle and lower catchment have

been totally cleared for agriculture on the hills with some pockets of native vegetation along the

river where the river is confined between steep hills.

The river flows out of the Strzelecki Ranges to the coastal plain near the township of Agnes. On

the coastal plain, the river continues to flow south through a small section of paperbark swamp

(Melaleuca ericifolia) and mangroves (Avicennia marina) to enter Corner Inlet and Noorumunga

Marine and Coastal Parks at Barry Beach.

Information about the environmental condition of Agnes River was assessed for South Gippsland

Water in SKM (2007) Agnes River Preliminarily Environment Assessment. The key outcomes of

that assessment of relevance to the WSDS are:

The Agnes River Falls are 59 m high and a natural barrier to fish movement through the

catchment.

There is limited native riparian vegetation and extensive willow infestation along the river in

most parts of the middle and lower catchments. Willows have been removed in some reaches

of the river and successfully revegetated with native riparian species.

The main risks to the aquatic fauna and flora in the Agnes River downstream of the Agnes

River Falls from reduced flows as a result of a reduction in low flows are likely to be:

– potential degradation of water quality;

– reduced available habitat for aquatic fauna (i.e. native fish); and

– potential impact on the condition of riparian vegetation and revegetation.

Water quality data indicates turbidity, total phosphorus and total nitrogen are above State

Environment Protection Policy guideline values. Consequently, any reduction in flow may

result in further lowering of water quality.



months.



Fourteen native fish species have been recorded in the Agnes River. Cox‟s Gudgeon

(Gobiomorphus coxii) and Australian Grayling (Prototroctes maraena) are considered

threatened in Victoria. Specifically, Cox‟s Gudgeon is considered endangered and Australian

Grayling is considered vulnerable. Both species are listed under the Victorian Flora and

Fauna Guarantee Act (FFG) 1988 and Australian Grayling is also listed as vulnerable under

the Commonwealth Environment Protection and Biodiversity Conservation Act (EPBC) 1999.

There is no record of the number of each of these species and it is uncertain whether these two

species are still present in the catchment as they have not been reported in recent surveys.

Water pools are an important summer refuge for aquatic fauna. Any premature drying of the

pools due to changes in summer flow regime could impact on ability of small bodied fish to

avoid larger predatory species.





Historical diversions to Toora, Welshpool, Port Welshpool and Port Franklin have declined

significantly in recent years, as shown in Figure 17-3. These diversions are recorded at the clear

water storage outlet and do not include an allowance for treatment plant utilisation. The decrease

in diversions is largely associated with reductions in major industrial demand. The closure of the

Bonlac Dairy in 2006 is the main reason for the most recent decline. The number of total

customers billed has increased marginally over the last few years. Major industrial water use

excluding Bonlac has fluctuated between 15-25 ML/yr from 2006/07 onwards.

Figure 17-3 Historical diversions and number of customers billed at Toora, Port Welshpool, Welshpool and Port Franklin

The populations of the four towns have decreased significantly over the last two decades, as shown

in Figure 17-4, with the total population decreasing from 1230 in 1981 to 887 in 2006. The number

of dwellings increased slightly from 2001 to 2006.

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Figure 17-4 Historical population in Toora, Port Welshpool, Welshpool and Port Franklin






covering South Gippsland Water‟s supply area. Toora, Welshpool, Port Welshpool and Port

Franklin are located within the South Gippsland Shire East SLA and account for around 15% of the

population within that SLA.



overestimated population growth between 2001 and 2006. Both growth projections anticipated

positive population growth when there was actually a decline in population. The Victoria in Future

projections were closer to the growth which actually happened. However, given the uncertainty of

future population, South Gippsland Water has considered two population forecasts, which include

the Victoria in Future projections and a higher Local Growth scenario that allows for faster growth

in urban centres within SLAs.

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Population - Toora, Welshpool, Port Welshpool, Port Franklin




Major industrial and lot development demand is an area of uncertainty for the future demand

projections. An allowance for an increase in demand of 104 ML/yr to the Barry Beach port

development has been explicitly allowed for in the Local Growth demand projections. The

timeframe for this demand has notionally been set to occur around the year 2020. This timeframe

is indicative only.

A 2.5% increase in residential and stock and domestic demand over the next 50 years was assumed

to occur due to medium climate change. This additional increase in demand is due to increased

water use for activities such as garden watering under drier and hotter climate change conditions

and is consistent with DSE recommendations (DSE, 2005).






evaporation. Under the ongoing low flow conditions scenario, Agnes River streamflows upstream

of Cook‟s Dam have been reduced by 33% prior to July 1997.

The Current Operation and Infrastructure water supply and demand situation for the Agnes River



accordance with population projections, demand under medium climate change is likely to exceed

available supply at South Gippsland Water‟s level of service objective if development occurs at

Barry Beach Port or by approximately 2034, whichever occurs earlier. Demand already exceeds

supply at South Gippsland Water‟s level of service objective under the ongoing low flow

conditions scenario.

Figure 17-5 Current Operation and Infrastructure Water Supply and Demand for Toora, Welshpool, Port Welshpool and Port Franklin


Three potential land use changes within the Agnes River catchment were investigated to

understand the potential risk that they could pose to available supply.

Bushfires: The maximum reduction in runoff after a bushfire typically occurs at around 10-20

years after the fire has occurred, and thereafter runoff progressively increases back to pre-bushfire

levels. 60% of the Agnes River catchment upstream of Cooks Dam has vegetation cover, however

there is no record of recent bushfires occurring in the South Gippsland region. The effect of

bushfire on catchment yield should therefore only be a problem if fires occur in this area in the

future.



Plantations: Plantations over a large proportion of a catchment can significantly reduce runoff to

downstream areas, particularly when those plantations are established on previously cleared land.

Up to one third of the Toora water supply catchment is covered by plantations, so this may have a

significant effect on catchment yield, depending on the age profile of the plantations.

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Allowance for potential development at Barry Beach Port ~2020

Further comments on the sensitivity of the Current Operation and Infrastructure projections to

demand uncertainty are also presented.

Future development: At Barry Beach in the Agnes River supply system, there has in recent years

been a concept proposal to construct a brown coal to urea plant with associated residential and

commercial development. The South Gippsland Shire Council (pers.comm. Jan 2011) advises that

this proposal is not currently active. However, from a longer term water resource planning

perspective, and also considering the potential for additional future water use associated with

possible development of Barry Beach port facilities, a future demand of 2 ML/wk (104 ML/yr) has

been assumed. This is in line with water resource investigations in 2008 (SKM, 2008a). For the

purposes of this strategy, this increase in demand has been assumed to occur in 2020. Further

details about the associated developments are currently uncertain and have not been explicitly

included in the major industrial demand forecasts.


If additional demand reduction options outlined in Section 4.10 are adopted for the Agnes River

system, the magnitude of future augmentation options would be slightly reduced, as shown in

Figure 17-6.

Figure 17-6 Effect of additional demand reduction options for Toora, Welshpool, Port Welshpool and Port Franklin

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17.7. Summary of the supply and demand for Toora, Welshpool, Port Welshpool and Port Franklin with current operation and infrastructure

In summary for Toora, Welshpool, Port Welshpool and Port Franklin under the Current Operation

and Infrastructure supply and demand scenarios:


objectives under medium climate change and is below those service objectives under a


Under the medium climate change scenario, demand for water is expected to exceed available

supply when the initial phase of the Barry Beach port development commences or by

approximately the year 2034, whichever occurs earlier;

Demand for water has fallen in recent years, primarily due to a reduction in major industrial

water use; and



A summary of South Gippsland Water‟s strategy for Toora, Welshpool, Port Welshpool and Port

Franklin in the context of South Gippsland Water‟s strategy for the central towns is presented in

Section 19.

18. Supply and Demand Projections for Unserviced Towns South of Fish Creek with Current Operation and Infrastructure

18.1. Introduction

This section of the WSDS outlines the demand projections for unserviced towns south of Fish

Creek over the next 50 years assuming current operation and infrastructure. These towns include

the existing towns of Walkerville, Waratah Bay, Sandy Point and Yanakie. None of these towns

are currently supplied by South Gippsland Water. Sandy Point, which is the largest of these four

towns, is approximately 15 km south of Fish Creek. South Gippsland Water‟s response to

supplying these unserviced towns is presented in Section 19 in conjunction with nearby serviced

towns.



Existing unserviced towns rely upon rainwater for their supply. New developments would need to

identify a source of water supply as part of their planning activities.


Residents in the unserviced towns can harvest rainwater in rainwater tanks. The availability of

other entitlements, such as groundwater licences, is unknown.


Sandy Point had a population of 205 in the 2006 census excluding visitors (DPCD, 2009). This

was less than one third of the number of dwellings, many of which are likely to be summer holiday

houses that were not occupied when the census was undertaken in winter. Census information was

not available for the remaining three unserviced towns. Large numbers of tourists are located in all

of these towns in the summer months. The current demand for individual towns and developments

was previously presented in Section 4.8. The current demand from these four towns is estimated to

total 259 ML/yr, of which 162 ML/yr is for Sandy Point.


Existing supply consists of privately owned rainwater tanks. It is estimated that reliability of

supply could be improved by connection to a supply source managed by South Gippsland Water.


Information on the environmental condition of the nearby Battery Creek, Deep Creek and Agnes

River supply systems was previously presented in the respective chapters on demand and supply

with current operation and infrastructure for Fish Creek, Foster and Toora respectively.



The population and number of dwellings at Sandy Point were not collected in censuses prior to

2006, hence there is no census information from which to derive historical trends in population or

the number of dwellings. The 2011 census will provide an indication of any trends in population or

the number of dwellings at Sandy Point. Trends at the remaining unserviced towns are unknown.





stronger growth within towns at a rate greater than the surrounding SLA. For the central towns,

both demand scenarios have been retained for this current strategy. The unserviced towns south of

Fish Creek have been assumed to grow at the same rate as Fish Creek, which for the Victoria in

Future projections include a growth in residential demand of up to 0.3% per year over the next few

years and then falling to no growth by around 2035. The Local Growth scenario assumes a 0.7%

annual growth rate in residential demand over the fifty year planning horizon.





Figure 18-1 Current Operation and Infrastructure water demand for unserviced towns south of Fish Creek

18.4.3. Future supply projections

Supply projections are considered in Section 19 as part of the strategy for Fish Creek, Foster and

Toora. The timing of the connection of the unserviced towns to South Gippsland Water‟s supply

systems is uncertain and it has been assumed in the strategy that it could occur around the year

2025. This would allow sufficient time for South Gippsland Water to undertake its planning and

design activities and then construct and commission the new supply system.


Potential land use changes within the catchments supplying Fish Creek, Foster and Toora were

investigated to understand the potential risk they could pose to available water supply. These were

previously documented in Sections 15.5, 16.5 and 17.5 respectively, and indicated that the risk of

changes in supply due to bushfires, logging and plantations in these catchments was low.


If the additional demand reduction options outlined in Section 4.10 were adopted for the unserviced

towns south of Fish Creek, the size of any future supply augmentation option could be minimised,

as shown in Figure 18-2.

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Figure 18-2 Effect of additional demand reduction options for unserviced towns near Inverloch

18.7. Summary of the supply and demand for unserviced towns south of Fish Creek with current operation and infrastructure

In summary for unserviced towns south of Fish Creek under the Current Operation and

Infrastructure supply and demand scenarios:

Existing supply consists of privately owned rainwater tanks;

The number of people currently permanently residing in Sandy Point is 205. This was less

than one third of the number of dwellings, many of which are likely to be summer holiday

houses that were not occupied when the census was undertaken in winter; and

Demand for water is estimated to currently be in the order of 259 ML/yr, but could increase up

to 350 ML/yr over the planning horizon;

South Gippsland Water‟s strategy to address the potential future supply to these unserviced towns

is presented in Section 19.

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19. Strategy for Central Towns

19.1. Introduction

This section of the document presents the demand reduction and supply enhancement strategy for

towns in South Gippsland Water‟s central region. These include the towns of Dumbalk, Meeniyan,

Foster, Fish Creek, Toora, Welshpool, Port Welshpool and Port Franklin. The strategy for these

towns is considered collectively, because one of the supply options involves interconnecting the

supply systems. The ability to supply unserviced towns south of Fish Creek, namely Sandy Point,

Walkerville, Waratah Bay and Yanakie, is also presented in this chapter.

The pros and cons of two strategies were considered by South Gippsland Water:

Supply from existing separate South Gippsland Water headworks – This strategy involves

upgrading South Gippsland Water‟s existing supply infrastructure and operating the supply systems

independently. Under this strategy, the unserviced towns would not be supplied by South

Gippsland Water. Details of this strategy for each town are presented in Section 19.2.

Supply from a linked system – This strategy involves connecting the Agnes River, Deep Creek

and Battery Creek systems to supply existing towns, with the option to supply unserviced towns

south of Fish Creek. Details of this strategy for each town are presented in Section 19.3.

A potential connection of the Melbourne system to these towns was briefly considered but

dismissed due to high costs and was not investigated further. The supply systems for Meeniyan

and Dumbalk, which may be merged to minimise water treatment costs, are only considered as

standalone systems in the WSDS as any decision to merge these two systems is not driven by

consideration of water resource availability.

19.2. Supply from existing South Gippsland Water headworks

19.2.1. Supply from existing headworks for Dumbalk, Meeniyan and Foster

The current operation and infrastructure supply and demand projections presented in previous

chapters of this document highlighted that existing supply is sufficient to meet South Gippsland

Water‟s current level of service objectives over the 50 year planning horizon. If operated as

standalone supply systems, no supply enhancement options would be required for these systems.

19.2.2. Supply from existing headworks for Fish Creek

Available supply to Fish Creek is not sufficient to cater for demands at South Gippsland Water‟s

level of service objectives, even after considering additional demand reduction. Hence the Battery

Creek supply system will require supply enhancement. Water supply options for Fish Creek were

previously outlined in SKM (2004) and included raising Battery Creek Reservoir and diverting

water from nearby Hoddle Creek into Battery Creek Reservoir. Raising Battery Creek Reservoir

by 150 ML in combination with supply from Hoddle Creek was found to increase the available

yield sufficient to meet current and future demands at Fish Creek. It also provides sufficient supply

if demands from rural water users in severe droughts were to return to the higher demand levels

observed prior to the 2006/07 drought and prior to the implementation of South Gippsland Water‟s

WaterMap initiative. Supply from Hoddle Creek was found to add limited supply to Fish Creek

unless it was accompanied by additional storage, which would most likely involve raising Battery

Creek Reservoir. This is because additional supply from Hoddle Creek would be within

Sustainable Diversion Limits during the winterfill period only.

The Battery Creek Reservoir has leakage and stability problems, which could result in piping

failure if remedial works are not undertaken. This need for remedial works provides an opportunity

for South Gippsland Water to save costs by undertaking both the remedial works and the raising of

the dam wall at the same time.

Figure 19-1 Effect of supply enhancement for Fish Creek




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Raise Battery Creek Reservoir by 150 ML and connect to Hoddle Creek

October to April, the availability of a large volume in storage means that South Gippsland Water

would be able to maintain supply through two consecutive years of repeating 2006/07 climate.

19.2.3. Supply from existing headworks for Toora, Welshpool, Port Welshpool and Port Franklin

Supply enhancement options for the Agnes River supply system were previously investigated in

SKM (2004), with further work being done to size an off-stream storage in SKM (2008a). The

2007 WSDS indicated that an additional 50 ML of storage would be sufficient to meet future

demands. Since that time, the 2006/07 drought occurred and developments are being proposed at

Barry Beach which could result in significantly increased demand.

SKM (2008a) provided a range of potential off-stream storage sizes. For the purposes of the

WSDS, a total system storage of 250 ML has been assumed (i.e. a net increase of 191 ML), which

was the largest storage size increase recommended in SKM (2008a). The option of staging the

storage increase was examined for South Gippsland Water in SKM (2010), which concluded that a

smaller storage could be adopted if the Barry Beach demand does not increase. Cook‟s Dam is

assumed to not be part of the supply system under normal operation, with all active storage

becoming off-stream. Under the demand assumptions in the WSDS, this results in yield exceeding

projected demands, however there is a high degree of uncertainty in future demands, which could

be much larger if future developments proceed. Decisions around an appropriate future storage size

are also affected by water quality considerations. The supply demand balance with this supply

enhancement option is shown in Figure 19-2.

Figure 19-2 Effect of supply enhancement for Toora, Welshpool, Port Welshpool and Port Franklin under medium climate change



analysis highlighted that even though local catchment inflows were zero or negligible in December

and January, the availability of a suitable volume in storage means that South Gippsland Water

would be able to maintain supply through two consecutive years of repeating 2006/07 climate.

19.2.4. Supply from existing headworks for unserviced towns south of Fish Creek

The ability to enhance supply in the Battery Creek supply system is limited, hence it is not

considered feasible to connect the unserviced towns south of Fish Creek to the Battery Creek

supply system, particularly given the potential for Fish Creek rural demands to increase in severe

drought years.

19.3. Supply from a linked system

As an alternative to the local supply enhancement options for Fish Creek and Toora, the option of

linking the supply systems for these towns together with the Deep Creek system was considered.

This option is only currently able to be considered because of a reduction in demand at all three

towns over the last few years which makes a linked system more feasible.

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Increase total system storage to 250 ML

A schematic of the proposed linked system is shown in Figure 19-3. This proposed configuration

assumes that treated water would be transferred between the clear water storages at Toora and

Foster, as well as from the clear water storage at Foster to the Fish Creek supply system. The

Foster to Fish Creek connection is sized to enable connection to the unserviced towns in the future.

Figure 19-3 Schematic of proposed linked system

A raw water transfer option was also considered but was dismissed due to higher costs associated

with longer pipe lengths.

The results of water resource modelling of the linked treated water supply option are shown in

Figure 19-4. The yield from the linked system is estimated to be 1,230 ML/yr, which under the

Victoria in Future scenario would be sufficient to provide supply to the three towns plus the

unserviced towns if connected around 2025. It would also provide a supply buffer if Fish Creek

rural demands increase in a very dry year prior to connecting the unserviced towns or if Barry

Beach demand increases beyond the demands during the construction phase. If the Local Growth

demand were to eventuate, then an additional 100 ML of off-stream storage would be required at

Toora under ongoing low flow conditions when the unserviced towns are connected.

Future demand at Barry Beach could potentially increase well beyond the current anticipated

demand. If the interlinking of the supply systems is combined with additional storage, then yield

could be further increased to cater for additional demand as required. Under ongoing low flow

conditions, additional storage of 100 ML at Toora would increase total system yield to

Fish Creek Rural

Fish Creek Urban

Battery Creek Reservoir

Deep Creek

Reservoir

Foster Dam

Foster to Fish Creek

Connection 2.0 ML/d Basin

Foster

Cooks Dam

Toora, Welshpool, Port Welshpool,

Port Franklin and

Barry Beach

Unserviced towns

Toora Basin

Supply to unserviced

towns1.5 ML/d

Supply to Fish Creek

0.5 ML/d

1,470 ML/yr, whilst an additional storage of 250 ML at Toora would increase yield to

1,830 ML/yr. Beyond this level of storage, South Gippsland Water‟s bulk entitlement limits for

diversion from the Agnes River are reached and additional yield achieved with additional storage is

small.

Figure 19-4 Supply from linked system for Fish Creek, Foster, Toora, Welshpool, Port Welshpool and Port Franklin



analysis highlighted that even though local catchment inflows were negligible in this year over the

summer period, the availability of a large volume in storage at Foster means that South Gippsland

Water would be able to maintain supply through two consecutive years of repeating 2006/07

climate.

19.4. Sustainability assessment of options

The introduction of demand reduction measures in line with other towns supplied by South

Gippsland Water will serve to minimise infrastructure costs and delay the need for supply

augmentations. On a sustainability assessment, demand reduction measures will be preferable to

augmenting the supply system, however in order to meet future demands both actions will be

required for some towns.

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Demand under medium climate change with future demand reduction measures




Allowance for potential development at BarryBeach Port ~2020 under local growth scenario

Unserviced towns south of Fish Creek connected ~2025

Systems interlinked 2012/13

Additional 100 ML storage at Toora ~2025 to meet unserviced towns demand under local growth scenario

The sustainability assessment for the central towns compares the option to supply from enhancing

existing headworks as standalone systems and the option to interlink the Deep Creek, Battery

Creek and Agnes River supply systems. The outcome of the assessment is summarised in Table

19-1 and indicates that the supply from an interlinked system has the advantage of greater

flexibility and robustness to potential future changes in demand and provides South Gippsland

Water with the option to provide reticulated supply to towns south of Fish Creek. A definitive

preferred strategy is dependent on the outcomes of further financial analysis, which is currently

being undertaken by South Gippsland Water. Key points to note about the sustainability

assessment are as follows:

The cost of upgrading the existing separate headworks on a comparable basis with the cost of

interlinking the systems is yet to be determined. South Gippsland Water is in the process of

undertaking this financial analysis.

The interlinked system would support more regional development by providing access to a

potable supply in the unserviced coastal towns south of Fish Creek and by providing greater

flexibility to service potential future industrial growth at Barry Beach in a staged manner. It

would also provide the ability to meet any increase in rural demands at Fish Creek in a very

dry year prior to the connection of the unserviced towns.

Greenhouse gas emissions associated with operation are low for both options, but marginally

higher under the interlinked supply option due to increased pumping. The greenhouse costs

associated with construction have not been included in this assessment.

River health would be similar for both options. River health would be expected to decline in

Hoddle Creek due to winter harvesting of water and construction of a weir on the creek under

the option to upgrade existing separate headworks. The interlinked option would involve

harvesting more water from the Agnes River and Deep Creek, but in both cases the volume

harvested would be within South Gippsland Water‟s current legal entitlements for water,

which include passing flows for river health.

Changes in water quality in local waterways would be expected to be negligible under both

options.

Both options would have a minor impact on other ecosystems. For the interlinked system,

vegetation would need to be cleared along the proposed pipeline route if it cannot be located in

an existing cleared service corridor. For the separate existing headworks option, there would

be expected to be minor loss of terrestrial habitat above the current full supply level of Battery

Creek Reservoir (but an increase in aquatic habitat) and a loss of terrestrial habitat at the

Agnes River off-stream storage site.

Both options are unlikely to have any impact on recreation and heritage activities in the area.

Interlinking the Deep Creek and Agnes River systems would allow more water to flow over

the Agnes River Falls, however the change in flow for recreational purposes may not be

noticeable to visitors.

Both options are likely to be socially acceptable, however some individuals may be affected by

either option. Raising Battery Creek Reservoir may result in the loss of some private land due

to inundation, whereas the connecting pipes for the interlinking option may need to cross

private land, depending on the final pipeline route selected.

There is a moderate degree of confidence associated with both options. The confidence

associated with the interlinked system is slightly higher, because it is less reliant on a single

supply source if water availability in any one of the Agnes River, Deep Creek or Battery Creek

were to change under climate change.

Table 19-1 Sustainability Assessment of Options for Central Towns(1)

(1) For broad comparison of options only. See Section 5.1 for further details of the function of this sustainability


19.5. Strategy summary

For the towns of Meeniyan and Dumbalk, no specific actions are required to maintain adequate

supply over the 50 year planning horizon, other than to introduce demand reduction measures in

line with other towns. Any decision to merge these two systems to minimise water treatment costs

is not driven by and will not affect water resource availability, and hence is not considered further

in this WSDS.

For the remaining central towns, the main uncertainty is associated with the potential demand for

water from Barry Beach and the unserviced towns south of Fish Creek. Whilst the interlinked

system offers greater flexibility and robustness to any increases in demand, South Gippsland Water

will undertake a financial analysis of these two proposed options in order to better understand the

risk profile of these options from a financial perspective. Pending the outcome of the financial

Net

pre

sent

cost

Regio

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develo

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Gre

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em

issio

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Riv

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health

Wate

r qualit

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Oth

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Culture

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and h

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Socia

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bili

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Confidence f

lag

LR

MC

($/M

L)


5 1 5 1 0 0 0 3 2 n/a

tbc 1 -1 -1 0 -1 0 3 2 tbc

Option: Interlink Battery Ck, Deep Ck and Agnes River treated water supply

tbc 2 -1 -1 0 -1 0 3 2 tbc

Option: Local supply enhancement (raise Battery Ck Reservoir with supply from Hoddle

Ck and increase storage at Toora up to 250 ML)

analysis, South Gippsland Water has presented a strategy below which considers the approach for

both strategies. South Gippsland Water will continue to monitor proposed developments at Barry

Beach as they are formed into more concrete proposals.

The approximate timing of infrastructure augmentation under each option is shown in Figure 19-5.

Figure 19-5 Approximate timing of South Gippsland Water infrastructure augmentation to maintain reliability of supply

Immediate and ongoing actions which are applicable to both options are listed in Table 19-2.

These include actions to monitor demands.

Table 19-2 Immediate and Ongoing Actions for Central Towns

Strategy Actions

Reduce uncertainty in current


- Compare quarterly or four monthly consumption data from

property and bulk meters

Reduce uncertainty in future


- Examine long-term trends in water use independent of

climate variability

Encourage demand reduction - Pursue additional demand reduction options after adoption

by WaterSmart

- Continue ongoing program of system leak reduction and

inspections for unmetered tappings

- Arrange interest free finance to farmers for installation of

facilities to reduce demand



Approx. Timing














20. Strategy for Eastern Towns

20.1. Introduction

This section of the WSDS outlines the demand and supply strategy for Yarram, Port Albert,

Alberton and Devon North over the next 50 years. It includes an overview of the current supply

system configuration, current demand for water and current supply. It also includes Current

Operation and Infrastructure supply and demand projections under future climate change and any

actions required to ensure that demand does not exceed supply in the long-term.



An offtake weir on the Tarra River supplies water to the townships of Yarram, Alberton, Port

Albert and rural areas in their proximity including Devon North. A schematic of the supply system

is shown in Figure 20-1. The river supplies other parties including rural users who utilise it for

domestic and stock purposes. From the offtake weir the supply gravitates to two storages at Devon

North of 3.4 ML and 30 ML capacity respectively. The 30 ML storage acts as raw water storage.

From here it passes through a treatment plant and is then transferred to the covered and lined

3.4 ML clear water storage. From here the supply gravitates to Yarram, Alberton and Port Albert.

The useable storage (“live” storage) in the system is estimated to be 31 ML. At Yarram there is a

270 kL capacity elevated tower, but this is not used because the minimum hydraulic grade line in

the reticulation system is always higher than the top water level of the tank. There is a 136 kL

elevated tower at Port Albert. Enroute from the Devon North storages to Yarram, supply is

provided to the community of Devon North and adjoining rural areas. Other rural supplies are

provided to properties between Yarram and Port Albert. Supply under specific agreement is

provided to properties between the offtake weir and the Devon North storages. Included in the

agreement is provision requiring the consumer to install security water storage tanks with a

minimum capacity of 45.4 kL. These properties are outside the South Gippsland Water‟s district

and the supply is unchlorinated.

South Gippsland Water has obtained in-principle approval from the licensing authority Southern

Rural Water to purchase up to 400 ML/yr of groundwater licences at Yarram for extraction at the

South Gippsland Water bore at a rate of up to 4 ML/d. This groundwater bore provides water to

the raw water basin at Devon North. South Gippsland Water also has a licence to extract

groundwater from a bore at the Yarram Golf Club at a rate of 1.0 ML/d up to a total annual volume

of 60 ML. This groundwater bore is not directly connected to the reticulated supply of the Yarram

supply system and temporary arrangements have to be made in times of drought to make this

emergency supply functional.

Figure 20-1 Tarra River Water Supply System schematic


The bulk entitlement for Yarram allows South Gippsland Water to divert up to a maximum of 853

ML/yr from the Tarra River. The daily bulk entitlement is shown in Table 20-1.

Table 20-1 Bulk entitlement volume for Yarram

Source Maximum

annual volume

(ML/yr)

Flow in Tarra River

upstream of offtake weir, F

(ML/d)

Flow available for

diversion

(ML/d)

Minimum passing

flow

(ML/d)

Tarra River 853 > 12 6 F – 6

6 – 12 0.5 * F 0.5 *F

3 – 6 F – 3 3.0

< 3 0 F

Note: F = flow in the Tarra River upstream of the offtake weir in ML/d

Details of South Gippsland Water‟s groundwater licences at Yarram are shown in Table 20-2. As

mentioned previously, South Gippsland Water has obtained in-principle approval from the

licensing authority Southern Rural Water to purchase up to 400 ML/yr of groundwater licences at

Yarram for extraction at the South Gippsland Water bore. The current permissible consumptive

volume from the Yarram Water Supply Protection Area is 25,317 ML/yr and peak annual usage in

the 2006/07 drought was only around 17,000 ML/yr (SRW, 2010), which suggests that trade of

currently unused licences to South Gippsland Water is likely to be readily achievable in the short-

term. Temporary transfer of licences is also possible in the interim if required prior to permanent

transfers occurring.

Table 20-2 Groundwater licence for Yarram

Location Annual licensed volume (ML/yr) Maximum extraction rate (ML/d)

Yarram – Golf Course 60 1

Yarram – South Gippsland Water

Bore

Transfer process underway 4


Yarram, Port Albert and Alberton had populations of 1589, 231 and 154 respectively excluding

visitors in the 2006 census (DPCD, 2009). This corresponds to a total of 1,974 for the three towns.

Population data for Devon North was not available. A demand model was fitted to the recent

unrestricted data to estimate a long-term average annual demand, which takes into account how

current demands would vary under a wider range of natural climate variability. The historical and

estimated long-term current demand is shown in Figure 20-2. The long-term average annual

demand is 560 ML/yr at South Gippsland Water‟s treatment plant inlet, of which around 4% is

utilised on average through the treatment plant.

Figure 20-2 Long-term monthly demands for Yarram, Port Albert, Alberton and Devon North


Restrictions have occurred relatively frequently in recent years at Yarram, with restrictions being

implemented around every second year on average over the last decade. This included severe

restrictions (Stage 4 of 4 stages or equivalent) in 2000/01, 2003/04, 2005/06 and 2006/07. Since

2006/07, the supply and demand balance has been improved through a reduction in demand and

through South Gippsland Water‟s access to additional groundwater supply at Devon North.

Reliability of supply modelling, which incorporates 400 ML/yr of additional groundwater supply,

indicated that restrictions would not have been required at current demands over the period of

modelling from July 1961 to June 2007. This meets South Gippsland Water‟s level of service

objectives to have restrictions not more frequently than in 10% of years. Further details on the

water resource model used to assess reliability of supply (and yield) can be found in SKM (2009).


The Tarra River catchment lies on the south face of the Strzelecki Ranges. Three tributaries join the

Tarra River, namely Macks Creek, Greig Creek and Bodman Creek. Spring Creek joins Bodman

Creek upstream of the Tarra River confluence. The Tarra River, Macks Creek and Greig Creek

originate within the Tarra Bulga National Park. The Tarra Bulga National Park has mountainous

terrain characterised by high rainfall and is covered by tall open forest of Mountain Ash

0

20

40

60

80

100

120

De

man

d f

rom

Tre

atm

en

t P

lan

t (M

L/m

th)

Historic

Estimated

Restrictions Demand Model Calibration Period (restrictions excluded)

(Eucalyptus regnans), Messmate (Eucalyptus obliqua) and Blackwood (Acacia melanoxylon) on

the hills and slopes and cool temperate rainforest of Myrtle Beech (Nothofagus cunninghamii),

Southern Sassafras (Atherosperma moschatum), Austral Mulberry (Exocarpus cupressiformis) and

Banyallas (Pittosporum bicolor) within the gullies (WGCMA, 2005). After leaving the national

park, the Tarra River flows through lowland hills in a predominantly rural landscape. The main

landuse in the area consists of sheep grazing and dairy production. From the hills, the change of

slope for the catchment is quite rapid and the mid to lower sections are quite flat and characterised

by lower rainfall than the upper catchment with an average annual rainfall of 600mm compared to

greater than 700 mm in the upper catchment (WGCMA, 2005). The Tarra River flows for

approximately 57 km from the headwaters, through Yarram, and continues to flow south to the

estuary before discharging to the sea downstream of Tarraville (Lieschke and Zampatti, 2001).

Information about the environmental condition of Tarra River was assessed for the West Gippsland

Catchment Management Authority in SKM (2006c). The key outcomes of that assessment of

relevance to the WSDS are:

The Tarra River has been identified as a Representative River in the Victorian River Health

Strategy and supports a number of significant species that have evolved with or rely directly or

indirectly on the natural flow regime of the Tarra River.

The natural flow regime of the Tarra River system has been significantly altered since

European settlement by the diversion of water for off stream uses. The change in flow regime

has had the greatest impact during the summer low flow period. There has been an increase in

the duration of low flows and a reduction in the magnitude of high flows following significant

rain events.

Once the rivers and creeks emerge from the Tarra Bulga National Park there is little native

vegetation along the creeks except for some pockets of remnant vegetation.

Water quality is generally moderate to good throughout the Tarra River catchment.

Nineteen species of native freshwater and estuarine species and one exotic fish species were

surveyed within the reaches of the Tarra River catchment. A number of marine species have

also been recorded in the river mouth and estuarine sections of the river (Lieschke and

Zampatti, 2001). Eleven of the native species are migratory and two are considered threatened

in Victoria. Cox‟s Gudgeon (Gobiomorphus coxii) is listed as endangered within Australia

and the Australian Grayling (Prototroctes maraena) is listed as vulnerable within Victoria

under the Flora and Fauna Guarantee Act 1988) (Lieschke and Zampatti, 2001). Australian

Grayling is also listed as vulnerable under the Environment Protection and Biodiversity

Conservation Act (EPBC) 1999.

The presence of Mountain Galaxias (Galaxias olidus) was confirmed in a survey in Spring

Creek which is outside its normal altitudinal range of this species (Lieschke and Zampatti,

2001).

Two species of burrowing crayfish, classified as rare in Victoria, have been recorded in the

catchment. These are the south Gippsland Spiny Crayfish (Euastacus neodiversus) and the

Strzelecki Burrowing Crayfish (Engaeus rostrogaleatus) (Lieschke and Zampatti, 2001).



Historical diversions to Yarram, Port Albert, Alberton and Devon North have declined slightly in

recent years, however most years have been affected by restrictions, so it is difficult to discern any

clear trends, as can be seen in Figure 20-3. These demands are recorded at the treatment plant

outlet and do not include an allowance for treatment plant utilisation. The number of customers

billed in this supply system has increased slightly over the last few years. This potentially indicates

that significant water savings have been achieved by South Gippsland Water and its customers in

recent years.

Figure 20-3 Historical diversions and number of customers billed at Yarram, Port Albert, Alberton and Devon North

0

150

300

450

600

750

900

1050

1200

1350

1500

0

100

200

300

400

500

600

700

800

900

1000

Nu

mb

er

of

cu

sto

mers

b

ille

d

His

tori

cal

Dem

an

d f

rom

Tre

atm

en

t P

lan

t (M

L/y

r)

Year beginning July

Demand



The population in the Tarra River system has declined in recent years, as shown in Figure 20-4,

with the total population decreasing from 2,055 in 2001 to 1,974 in 2006. This was largely due to a

decline in population at Yarram. There was a slight increase in population at Port Albert. The

number of dwellings was however shown to increase steadily over the last two decades.

Figure 20-4 Historical population in Yarram, Port Albert, Alberton and Devon North(1)

(1) No census data available for Devon North. Alberton data only available from 2001 onwards.






covering South Gippsland Water‟s supply area. Yarram, Port Albert, Alberton and Devon North

are located within the Wellington Shire Alberton SLA and account for around 35% of the

population within that SLA.




closer to the growth which actually happened, which was a decline in population of 4%. However,

0

500

1000

1500

2000

2500

1981 1986 1991 1996 2001 2006

Po

pu

lati

on

/ D

we

llin

gs

Dwellings - Yarram, Port Albert, Alberton and Devon North

Population - Yarram, Port Albert, Alberton and Devon North





the next few years, with a decline in population anticipated from 2012 onwards of up to 0.5% per

year. The Local Growth scenario assumes a 0.25% annual growth rate in residential demand over

the fifty year planning horizon.

A 2.5% increase in residential and stock and domestic demand over the next 50 years was assumed

to occur due to medium climate change. This additional increase in demand is due to increased

water use for activities such as garden watering under drier and hotter climate change conditions

and is consistent with DSE recommendations (DSE, 2005).






evaporation. Under the ongoing low flow conditions scenario, Tarra River streamflows upstream

of the town offtake have been reduced by 50% prior to July 1997.

The Current Operation and Infrastructure water supply and demand situation for the Tarra River


figure illustrates that demand is not expected to exceed available supply in the foreseeable future

for the Victoria in Future scenario. Under the Local Growth scenario, demand would be expected

to exceed supply at South Gippsland Water‟s level of service objective just before the end of the

fifty year planning horizon.

Figure 20-5 Current Operation and Infrastructure Water Supply and Demand for Yarram, Port Albert, Alberton and Devon North


Several potential land and water use changes within the Tarra River catchment were investigated to

understand the potential risk that they could pose to available supply.

Bushfires: The maximum reduction in runoff after a bushfire typically occurs at around

10-20 years after the fire has occurred, and thereafter runoff progressively increases back to pre-

bushfire levels. Approximately 88% of the Tarra River catchment upstream of the Yarram offtake

is covered by vegetation and could be susceptible to bushfire. There is no record of bushfires

occurring in this water supply catchment in recent decades. The effects of bushfire on catchment

yield will therefore only be a concern if fires occur in this area in the future.

Logging: Only a very small proportion (<5%) of the water supply catchment is covered by areas

subject to logging under Regional Forestry Agreements. Water supply to Yarram is therefore not

considered to be at risk due to logging.

Plantations: A significant proportion (~40-60%) of the Yarram water supply catchment is covered

by plantations. Plantations over a large proportion of a catchment can significantly reduce runoff

to downstream areas, particularly when those plantations are set up on previously cleared land or

where the species is switched from native forest to pine plantations. A significant proportion of the

Yarram water supply catchment is covered by plantations, so this may have a significant effect on

400

450

500

550

600

650

700

750

2009 2014 2019 2024 2029 2034 2039 2044 2049 2054 2059

Vo

lum

e (M

L/y

r)





catchment yield, depending on the age profile of the plantations. Local operators estimate the age

of the plantations to be around 20-30 years, that they consist of a mixture of eucalypt and pine

plantations and that they were originally planted on previously cleared land. On this basis, it is

likely that streamflow yields per unit catchment area have changed over time such that the

historical streamflow record does not accurately represent current streamflow conditions. DSE

recently developed a tool for estimating changes in runoff associated with changes in land use type,

which may provide South Gippsland Water with useful information about how its water availability

will change over time as a result of harvesting and replanting of the plantations.

Groundwater level decline: Groundwater levels in the Gippsland coastal region near Yarram have

been declining at around 1 m/yr for the last twenty years predominantly due to off-shore oil, water

and gas extraction (SRW, 2010). This trend is expected to continue for the next few decades.

South Gippsland Water has designed its groundwater bore and pump to be able to cope with

regional reductions in groundwater level over the design life of the bore. The Yarram WSPA

Groundwater Management Plan (SRW, 2010), which governs the management of groundwater

extraction in the region, acknowledges this decline. There are not currently any defined triggers for

cessation or restriction of groundwater pumping across the region associated with the decline. The

Groundwater Management Plan is subject to annual reporting by Southern Rural Water, which

would indicate any proposed changes to plan rules. Any such changes must be publically consulted

on prior to adoption.

Growth in water demand: CEE (2006) held discussions with individual landholders to investigate

rural water use. The range of water used on individual farms is shown in Figure 20-6. In the farms

with high water use, water is used for washing out dairies, cleaning milk equipment, drinking water

for stock and supplying residences on the farms. The farms using little water are generally only

supplying the farmhouse. Discussions with two large farm water users revealed that demand for

water is expected to stay much the same as at present.

Figure 20-6 Water use by farmers in the Tarra River urban supply system (from CEE, 2006)


If the additional demand reduction options outlined in Section 4.10 are adopted for Yarram,

Alberton, Port Albert and Devon North, demands would remain below the available supply, as

shown in Figure 20-7. With demand reduction measures, supply enhancement under the Local

Growth scenario would no longer be required near the end of the fifty year planning horizon.

Yarram Water Supply

Water use by Farmers

0

1

2

3

4

5

6

7

8

9

1 5 9 13 17 21 25 29 33 37 41 45 49 53 57 61 65 69 73 77 81 85 89 93 97 101 105 109 113 117 121 125 129

Property

Wate

r u

se

, M

L

Average use = 0.8 ML/year/property

Total use = 106.5 ML/year

Figure 20-7 Effect of additional demand reduction options for Yarram, Alberton, Port Albert and Devon North

20.7. Supply enhancement options

Available supply is expected to remain above future demands, even after considering climate

change, hence Yarram does not require any supply enhancement over the 50 year planning horizon

of this strategy.

South Gippsland Water‟s previous WSDS (South Gippsland Water, 2007) investigated the option

of additional off-stream surface water storage at Yarram, because the rules governing future

groundwater supply at that time were uncertain. However with the finalisation of the Yarram

Water Supply Protection Area Groundwater Management Plan in 2010 (SRW, 2010) this

uncertainty was reduced and groundwater supply was considered to provide much greater

reliability of supply at lower cost for the eastern towns than pursuing additional off-stream surface

water storage.

The resilience of the supply system to severe prolonged drought was examined by estimating

supply system behaviour under a repeat of the 2006/07 severe drought year. This analysis

highlighted that even though local catchment inflows were negligible in this year from October to

April, the availability of groundwater supply means that South Gippsland Water would be able to

maintain supply through two consecutive years of repeating 2006/07 climate.

400

450

500

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700

750

2009 2014 2019 2024 2029 2034 2039 2044 2049 2054 2059

Vo

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e (M

L/y

r)







20.8. Sustainability assessment of options

The only actions for South Gippsland Water in managing its eastern towns is to continue its

purchasing of groundwater licences up to the pre-approved limit and secondly to introduce demand

reduction measures in line with other towns supplied by South Gippsland Water. Whilst there is no

specific need for demand reduction for the eastern towns, implementing demand reduction

initiatives in these towns will ensure a consistent demand reduction message across South

Gippsland. It will also provide a buffer if strong growth does subsequently occur, despite current

predictions. The installation of water efficient devices, such as shower heads, will have a design

life of several decades and retrofitting is an expensive exercise.

Table 20-3 Sustainability Assessment of Options for Yarram, Alberton, Port Albert and Devon North

(1)

Net pre

se

nt cost

Regio

na

l

develo

pm

ent

Gre

enho

use

em

issio

ns

Riv

er

he

alth

Wate

r qua

lity

Oth

er

ecosyste

ms

Culture

, re

cre

atio

n

and h

erita

ge

Socia

l acce

pta

bili

ty

Confide

nce fla

g

LR

MC

($

/ML)


5 1 5 1 0 0 0 3 2 n/a (1) For broad comparison of options only. See Section 5.1 for further details of the function of this sustainability


20.9. Strategy summary

A summary of the long-term Water Supply Demand Strategy for Yarram, Alberton, Port Albert and

Devon North is shown in Table 20-4.

Table 20-4 Strategy for Yarram, Alberton, Port Albert and Devon North

Strategy Actions Timing

Reduce uncertainty in

current estimate of

consumer demand

- Compare quarterly or four monthly consumption

data from property and bulk meters

Immediate

Reduce uncertainty in

future estimate of

consumer demand

- Examine long-term trends in water use

independent of climate variability

ongoing

Encourage demand

reduction

- Pursue additional demand reduction options after

adoption by WaterSmart

- Continue ongoing program of system leak

reduction and inspections for unmetered tappings

2010 onwards

ongoing

Maintain reliability of

supply

- Continue transferring groundwater licences from

existing users up to the 400 ML/yr pre-approved

limit

Immediate

21. Strategy for Other Unserviced Towns

In addition to the unserviced towns near Inverloch and south of Fish Creek, which were previously

discussed in Sections 11 and 18 respectively, there are a number of small towns in the South

Gippsland region that are not currently connected to water or sewerage services. The viability of

supplying these towns was discussed in SKM (2004) and included the following geographical

groupings:

Bena, which is a small town of around 54 lots located between Korumburra and Loch.

Tarwin, which is a hamlet of around 12 lots between Koonwarra and Meeniyan.

Towns east of Yarram, which include Greenmount, Won Wron, Woodside, Woodside Beach,

Robertson‟s Beach, Manns Beach and McLoughlins Beach. All of these towns have less than

50 lots each.

Current and future demand for water from these towns was presented in Section 4.8 and totalled an

additional 130 ML/yr over the 50 year planning horizon. As previously noted in Section 4.8, there

remains much uncertainty about what future impact unserviced towns may have on existing supply

systems. It may well be that innovative approaches to how additional water is provided to such

existing communities will result in water requirements being much less than the values assumed in

this study.

Bena and Tarwin are currently considered too small to feasibly connect them to existing supply

systems, because the cost of connecting pipelines would be too high relative to the return from

customers supplied.

For the towns east of Yarram, South Gippsland Water‟s 2004 long-term planning strategy (SKM,

2004) identified potential pipeline routes to connect these towns to the Yarram system. Supply

from groundwater or local desalination may also be options to supply these towns. A discussion of

the general pros and cons of various alternative water supply options to these unserviced towns is

presented in Appendix B. Given that there is currently no demand for a reticulated supply in these

towns and given the likely high cost of supplying water to these small towns, South Gippsland

Water is not pursuing further investigations into supplying these unserviced towns at the current

time.

22. Conclusions

This Water Supply Demand Strategy (WSDS) for South Gippsland Water (South Gippsland Water)

provides a 50 year outlook of the supply and demand balance for each of South Gippsland Water‟s

supply systems. Future planning has been based on considering two climate change scenarios and

making an allowance for anticipated future population and industry growth under two alternative

growth scenarios. The key outcomes from the assessment process were:

Significant water savings have been achieved by South Gippsland Water and its customers in

recent years.

Further demand reduction will be pursued in all supply systems with a target set for:

– 25% reduction in per capita demand by the year 2015 relative to 1990s average demand;

– 30% reduction in per capita demand by the year 2020 relative to 1990s average demand.

These demand reductions will be insufficient to maintain supply at South Gippsland Water‟s

level of service objective for reliability of supply in some supply systems over the 50 year

planning horizon. Supply augmentation will be required in these systems.

For South Gippsland Water’s northern and southern towns, which includes Poowong,

Loch, Nyora, Korumburra, Leongatha, Wonthaggi, Cape Paterson and Inverloch:

– Supply enhancement is required within the next few years for Poowong, Loch, Nyora and

Korumburra.

– Future supply requirements for Leongatha are dependent on whether proposed water

savings at Murray Goulburn result in a reduction in demand from South Gippsland

Water‟s reticulated supply. Additional supply would be required by around 2020 if

Murray Goulburn demands remain at current levels.

– A business case is currently underway which is considering the financial costs and

benefits and associated risk profile for two alternative supply strategies for the northern

and southern towns. These include supply from enhancing existing separate South

Gippsland Water headworks or supply from an interlinked system connected to Lance

Creek Reservoir and the Melbourne supply.

– Preliminary outcomes from the business case and this WSDS indicate that the connection

to the Melbourne supply option has the advantage of being more robust to changes in

streamflow under climate change and potential increases in demand under the Local

Growth scenario. It is also more resilient to severe prolonged drought. This option also

potentially improves river health with the possibility of decommissioning existing on-

stream storages in the Tarwin and Bass River catchments. Both options were of similar

cost at the preliminary costing stage. A definitive preferred strategy is dependent on the

outcomes of the business case.

Both options would allow the potential to connect the nearby unserviced towns of Venus

Bay and Tarwin Lower, which would increase South Gippsland Water‟s customer base by

up to 1,000 ML/yr at the end of the 50 year planning horizon.

For South Gippsland Water’s central towns, which includes Dumbalk, Meeniyan, Foster,

Fish Creek, Toora, Port Welshpool, Welshpool and Port Franklin:

– Dumbalk, Meeniyan and Foster have sufficient supply to meet demands at South

Gippsland Water‟s level of service objective for reliability of supply over the 50 year

planning horizon.

– Supply enhancement is required within the next few years for Fish Creek and towns

currently supplied by the Agnes River (Toora, Port Welshpool, Welshpool and Port

Franklin).

– Two alternative supply strategies were considered for the central towns, namely enhancing

existing separate South Gippsland Water headworks or supply from an interlinked system

connecting Foster, Fish Creek and Toora.

– A preliminary assessment indicated that the interlinked system has the advantage of

greater flexibility and robustness to potential future changes in demand at Barry Beach

and provides South Gippsland Water with the option to provide reticulated supply to the

currently unserviced towns south of Fish Creek. These unserviced towns include Sandy

Point, Walkerville, Waratah Bay and Yanakie. A definitive preferred strategy is

dependent on the outcomes of further financial analysis, which is currently being

undertaken by South Gippsland Water.

For South Gippsland Water’s eastern towns, which include Yarram, Port Albert, Alberton

and Devon North:

– South Gippsland Water‟s current program to purchase up to 400 ML/yr of groundwater

licences from existing licence holders for use at its newly constructed bore is expected to

be sufficient to meet South Gippsland Water‟s level of service objective for reliability of

supply over the 50 year planning horizon.

A plan of system wide actions is shown in Table 22-1, along with specific actions for each group of

towns in Figure 22-1 to Figure 22-3.

The WSDS will be reviewed and updated every 5 years to incorporate additional hydrologic data,

changes in demand for water, changes in community expectations and improvements in scientific

knowledge. There are several areas of uncertainty for South Gippsland Water in developing the

WSDS, which will need to be monitored on an ongoing basis.

Table 22-1 Action plan – system wide actions

A. Demand Management

1 Reduce uncertainty in current and future estimates of consumer demand through

ongoing monitoring and metering, particularly for major industrial water users

2 Continue current successful water conservation initiatives, including the WaterMap

program for major industrial and rural customers

3 Actively pursue opportunities for the use of treated wastewater to offset potable supply

B. System Management

4 Reduce water leaks and wastage in reticulation systems and water treatment processes

5 Secure dams against leakage and future failures

C. Management for Forward Planning

6 Monitor stream flows and possible climate change

7 Monitor catchments to ensure reliable supply and quality of water

8 Encourage the use of alternative water sources where appropriate

9 Develop long term plan to extend water supply to unserviced towns

10 Monitor demographic trends, and hence potential demand for water, in cooperation with

DSE and local planning authorities

Figure 22-1 Action Plan for Northern and Southern Towns (preferred option dependent on business case outcomes)



Approx. Timing












Approx. Timing









Figure 22-2 Action Plan for Central Towns (preferred option dependent on financial analysis outcomes)

Figure 22-3 Action Plan for Eastern Towns



Approx. Timing














Approximate Timing

Action

2011 Continue purchasing groundwater licences up to 400 ML/yr from existing licence holders

23. References

Alluvium (2008) Determination of Environmental Flow Requirements for the Powlett River. Final

Recommendations. September 2008. Prepared for South Gippsland Water and the West Gippsland

Catchment Management Authority.

Bartley Consulting (2006) South Gippsland Water – Water Supply and Demand Strategy Proposed

Stakeholder Consultation Plan.

Bartley Consulting (2007) Feedback from Community Consultations. (Draft) Long Term Water

Supply Demand Strategy. Prepared for South Gippsland Water. March 2007.

CEE (2006) Water Supply and Demand Management Strategy for South Gippsland Water 2005-

2035. Consulting Environmental Engineers.

City of Salisbury (2010) Aquifer Storage and Recovery.

CSIRO (2006) Urban Stormwater.

Department of Water, Land and Biodiversity Conservation, 2010. Aquifer Storage and Recovery in

SA Fact Sheet.

DPCD (2009) Towns in Time.

http://www.dse.vic.gov.au/DSE/dsenres.nsf/LinkView/E05D934749B13CE2CA256D3B0005539F

5D8F38B915AF5AA1CA256D1A0022BDE9 Accessed 20/8/2009. Department of Planning and

Community Development.

DPCD (2010) Victoria in Future 2008. http://www.dpcd.vic.gov.au/home/publications-and-

research/urban-and-regional-research/victoria-in-future-2008. Department of Planning and

Community Development.

DPI (2007) A Guide to the Inland Angling Waters of Victoria. Department of Primary Industries,

Victoria. http://www.dpi.vic.gov.au/angling/27W-

SouthGippslandWest/Basin%20TEMPLATE%20Waters.htm

DSE (2004) Securing our Water Future Together. Victorian Government White Paper. Victorian

Department of Sustainability and Environment.

DSE (2005) Guidelines for the Development of a Water Supply Demand Strategy. Victorian

Department of Sustainability and Environment.

http://www.dse.vic.gov.au/DSE/dsenres.nsf/LinkView/E05D934749B13CE2CA256D3B0005539F5D8F38B915AF5AA1CA256D1A0022BDE9

http://www.dse.vic.gov.au/DSE/dsenres.nsf/LinkView/E05D934749B13CE2CA256D3B0005539F5D8F38B915AF5AA1CA256D1A0022BDE9

http://www.dpcd.vic.gov.au/home/publications-and-research/urban-and-regional-research/victoria-in-future-2008

http://www.dpcd.vic.gov.au/home/publications-and-research/urban-and-regional-research/victoria-in-future-2008

http://www.dpi.vic.gov.au/angling/27W-SouthGippslandWest/Basin%20TEMPLATE%20Waters.htm

http://www.dpi.vic.gov.au/angling/27W-SouthGippslandWest/Basin%20TEMPLATE%20Waters.htm

DSE (2008) Augmentation of the Melbourne Water Supply System. Analysis of Potential System

Behaviour.

DSE (2010) Draft Gippsland Region Sustainable Water Strategy for Community Comment. August

2010. Victorian Department of Sustainability and Environment.

DSE (2010b) Bayside Planning Scheme

EPA Victoria, 2010. Stormwater Harvesting and Use

Essential Services Commission (2010) Water Performance Report - Performance of Victorian

Urban Water & Sewerage Businesses 2009-10.

GHD (2003) Long Term Water Strategy for Unserviced Towns. Report. December 2003. South

Gippsland Water.

Jones, R.N. and Durack, P.J. (2005) Estimating the Impacts of Climate Change on Victoria’s

Runoff using a Hydrological Sensitivity Model, CSIRO Marine and Atmospheric Research,

Melbourne, 46 pp.

Lieschke, J. A. and Zampatti, B. P. (2001). An assessment of the Environmental flow requirements

for the Tarra River catchment. A component of the Tarra River Streamflow Management Plan. A

Report prepared for Southern Rural Water by Freshwater Ecology, Arthur Rylah Institute for

Environmental Research, December, 2001.

Lloyd Environmental in association with WaterTechnology, Ecological Associates and Fluvial

Systems (2008) Environmental Water Requirements of the Bass River. Final Recommendations.

Prepared for Melbourne Water.

Melbourne Water and Port Phillip and Westernport Catchment Management Authority (2005) Port

Phillip and Westernport Region Regional River Health Strategy. Draft for consultation.

Minister for Planning (2009) Victorian Desalination Project Assessment under Environment Affects

Act 1978.

Erlanger, P. and Neal, B. (2005) Framework for Urban Water Resource Planning. Water Services

Association of Australia Occasional Paper No. 14 – June 2005.

SKM/CRCFE (2002) Recommendations for Sustainable Diversion Limits over Winterfill Periods in

Unregulated Victorian Catchments. Sinclair Knight Merz and the Cooperative Research Centre for

Freshwater Ecology. Department of Natural Resources and Environment.

SKM (2003a) Drought Response Plan. Final DRP – Version G. October 2003. South Gippsland

Water.

SKM (2003b) Supply System Augmentation. Final – Version E. October 2003. South Gippsland

Water.

SKM (2004) Long-term Water Planning Strategy. Final. 8/07/2004

SKM (2006a) Coalition Creek Preliminarily Environment Assessment. Report prepared for South

Gippsland Water.

SKM (2006b) Tarwin River Preliminary Environment Assessment. Report prepared for South

Gippsland Water.

SKM (2006c) Tarra River Environmental Flows Assessment: Site Paper. Report prepared for

South Gippsland Water.

SKM (2007) Agnes River Preliminary Environment Assessment. Report prepared for South

Gippsland Water.

SKM (2008a) Sizing a Storage in the Toora Urban Water Supply System. Report prepared for

South Gippsland Water.

SKM (2008b) Assessment of Groundwater Licence Application at Leongatha.

SKM (2009) REALM Modelling to Support SGW’s Water Supply Demand Strategy. Report

prepared for South Gippsland Water.

SKM (2009) Tarwin River Environmental Flows Assessment. Recommendation Report. Final. 4

August 2009. Prepared for the West Gippsland Catchment Management Authority.

Southern Rural Water (2010) Groundwater Management Plan. Yarram Water Supply Protection

Area.

South Gippsland Water (2007) Water Supply Demand Strategy – Submission to Government.

Final. 6 June 2007.

TWGWSA (2005) Water Savings from Restrictions: Technical Report. Prepared for the

Metropolitan Drought Co-ordination Group and Victorian Water Industry Association by the

Technical Working Group on Water Savings Assessment. August 2005.

Verdon-Kidd, D.C. and Kiem, A.S. (2009) Nature and Causes of Protracted Droughts in South-

East Australia: Comparison between the Federation, WWII and Big Dry Droughts. Geophysical

Research Letters VOL. 36, L22707, doi:10.1029/2009GL041067, 2009

Victorian Government (2003). State Environment Protection Policy (SEPP) (Waters of Victoria) S

107.

VWQDW (2007). Victorian Water Quality Data Warehouse. Victoria Rivers Index of Stream

Condition http://www.vicwaterdata.net/vicwaterdata/data_warehouse_content.aspx?option=5

WaterSmart (2006) Water Supply Demand Strategy for Melbourne, 2006-2055. Technical Report

#1. Demand Baseline Forecast and Water Conservation (Demand Management) Options. April.

WGCMA (2005) West Gippsland River Health Strategy. West Gippsland Catchment Management

Authority.

WGCMA (2006) Freshwater macroinvertebrate monitoring of willow and willow reduced sites in

the South Gippsland Basin (2000-2006). Report prepared by Kerry Mathews for West Gippsland

Catchment Management Authority.

http://www.vicwaterdata.net/vicwaterdata/data_warehouse_content.aspx?option=5

Appendix A Self-audit checklist

This self-audit checklist from the WSDS guidelines has been included to confirm that the document

includes the necessary components of a WSDS.

Table 23-1: Self-Audit Checklist, Expected Outputs

Checklist Item Yes/No

?

Reference

in WSDS

Description of Current Water Supplies

Has the existing water supply system been briefly described? Yes Section 1.2

and X.2

Has a map or schematic of the water supply area been included? Yes Section 1.2

Has a list of regulatory plans governing water resources

management in the supply area and their relevance to the WSDS

been compiled?

Yes Section 3

Has any recent long-term planning undertaken by the water

authority been summarised?

Yes Section 1.3

Have the authority‟s legal entitlements to water been listed? Yes Section 3

Has the current average annual demand from the system been

quantified?

Yes Section 4.3

Has the yield of the system, and associated system reliability

criteria been quantified?

Yes Section

X.2.4

Have the current demand and system yield been compared? Yes Section X.4

Forecasting of Water Demand

Have current demand management initiatives and their

effectiveness to date been summarised?

Yes Section 4.9

Has the forecast “current condition” average annual demand been

forecast over the 50 year period of assessment for residential

/commercial, industrial and supply by agreement customers?

Yes Section 4.4,

4.5 and 4.6

Have key assumptions behind the demand forecast been

described?

Yes Section 4.4,

4.5 and 4.6

Reduction of Demand and Enhancement of Supplies

Has future demand and existing system yield been graphically

depicted?

Yes Section X.4

Has the magnitude of any future demand that cannot be met

through existing system yield been graphically depicted?

Yes Section X.4


?

Reference

in WSDS

Has the target reduction in water consumption to be achieved over

the next two regulatory periods been defined?

Yes Section

4.10

Has the target reduction in both raw and per capita water

consumption to be achieved over the period of assessment been

defined?

Yes Section

4.10

Has a description been provided on the measures to be employed

to achieve these reductions, particularly those that rely on

government policy, including the social, environmental, economic

and technical aspects associated with those measures?

Yes Section

4.10

Has the evaluation of options for water supply option

investigations considered social, environmental, economic and

technical aspects?

Yes Section

12.4, 19.4,

20.8

Has the authority confirmed that proposed supply options accord

with current regulations, legislation, and Victorian Government

policy?

Yes Section 3,

12, 19, 20

Has the authority identified and investigated the place of

alternative water resources in future supply options such as;

recycled water, rainwater, stormwater, and groundwater for both

existing serviced areas, and in particular new growth areas?

Yes Section 12,

19, 20,

Section 3,

Section

4.10

Have future investigations been proposed and lead times

identified to refine and then implement specific supply options?

Yes Section 12,

19, 20

Management of Risk and Uncertainty

Have the major uncertainties associated with water supply and

demand forecasts been defined?

Yes Section X.5

Have those major uncertainties been addressed by contingencies

in the timeline to implement the outcomes of the WSDS?

Yes Section X.5

As part of the identification of major uncertainties, has the

uncertainty of supply and demand projections due to climate

change been assessed:

Yes Section X.5

For small supply systems: with a qualitative assessment based on

readily available information?

Yes Section X.5

For large supply systems: with a quantitative assessment based on

a representative case study with the water authority‟s supply area?

Yes Section X.5

For cities: with a quantitative assessment of the supply system? N/a N/a


?

Reference

in WSDS

Assessment of Options and Development of Plans

Has the process used to assess and rank options been described? Yes Section 5

Is there a list of preferred actions for the next five years arising

from the WSDS?

Yes Section 12,

19, 20

Is there a prioritised list of long-term actions for the next fifty

years arising from the WSDS?

Yes Section 12,

19, 20

Have the socio-economic, environmental and financial costs and

benefits associated with those preferred actions been assessed?

Yes Section 12,

19, 20

Does the financial analysis include the up-front capital cost,

annual operation and maintenance costs, net present cost and net

present cost per ML or incremental yield (where relevant)?

Yes Section 12,

19, 20

Does the social analysis include consideration of any potential

impacts on other consumptive water users?

Yes Section 12,

19, 20

Consultation with Stakeholders

Has the consultation process and the key stakeholders consulted

been documented?

Yes Section 1.6

Have the outcomes of the consultation process been documented? Yes Section 1.6

Note: “X” refers to individual chapters of the supply and demand projections under current

operation and infrastructure.

Appendix B Alternative Water Supply Options for Unserviced Coastal Towns and Developments

This appendix provides an introduction to alternative water supply options for unserviced coastal

towns and developments. Most the coastal towns in the South Gippsland region are remote from

South Gippsland Water‟s existing infrastructure. This means that connecting them to South

Gippsland Water‟s existing supply network is not necessarily the most cost-effective solution,

because of the long pipe and pump networks required. It may therefore be more viable to develop

local alternative supply options. This appendix discusses some of the advantages and disadvantages

associated with five different alternative supply options for isolated coastal towns:

Bore water

Rain water

Grey water

Storm water

Local desalination of sea water

B.1 Summary

The relative advantages and disadvantages of each alternative supply option can vary for each

particular coastal town, however general statements can be made about each option for the region,

as listed in Table 23-2. Each of these options has been assessed in qualitative terms relative to one

another and not relative to connecting to South Gippsland Water‟s existing water supply network.

Key points to note are as follows:

Only groundwater and desalination provide a total water supply solution. Rainwater,

greywater and stormwater can be valuable components of an alternative water supply system,

but will not be adequate in isolation because of low reliability and/or high treatment costs to

create a potable supply.

Desalination viability is relatively invariable, subject to environmental sensitivities

surrounding discharge of the waste stream at individual sites.

Groundwater viability is highly site specific, as groundwater quality and yield vary

considerably from site to site.

Existing unserviced towns will already have rainwater tanks. The incremental cost of

supplying unserviced towns will be lower if existing rainwater tanks can be utilised as part of

the water supply system for these towns.

Rainwater, greywater and stormwater can be important source substitution measures for

new developments. The cost effectiveness of introducing rainwater tanks, greywater systems

and stormwater systems can be greatly improved if these systems are integrated into the design

of new developments. This requires the Authority to work closely with developers to provide

them with appropriate design parameters.

Table 23-2 Summary of relative advantages and disadvantages

Relative performance

measure

Alternative supply option

Groundwater Rainwater Greywater(1) Stormwater(1) Local Desalination

Capital cost Moderate Low Low Moderate High

O&M cost Moderate Low Low Moderate High

Reliability of supply High Low Moderate Low High

Energy consumption High Low Low Low High

Health risk Low Moderate High High Low

Suitability for potable supply High High Low Low High

(1) Assumed to be untreated for non-potable use only

Coming up with an integrated solution will need to consider the costs and benefits of each option,

as well as combinations of options for each individual town or development. The incremental cost

to South Gippsland Water customers associated with the preferred supply option combination will

then need to be estimated and consulted upon with the relevant community.

More information on each particular alternative supply option is provided below.

B.2 Bore water

Groundwater has the advantage of being generally cheaper than other supply options if aquifers are

located close to towns and because the supply is generally very reliable. Groundwater has

historically been a less favoured source of supply for South Gippsland Water because aquifers

close to towns are typically low yielding and often have high iron and manganese content which

can be difficult to treat as part of a blended supply.

High yielding, good quality aquifers to the east of Yarram (for Greenmount, Robertsons Beach,

Manns Beach, Won Wron, Woodside, Woodside Beach and McLoughlins Beach) are already fully

allocated within the Yarram Water Supply Protection Area and cannot be accessed without

purchasing licences from existing licence holders.

Yields across much of Gippsland can be as low as 15 ML/yr per bore, as documented in SKM

(2004) for each of South Gippsland Water‟s supply systems, indicating that dispersed borefields

rather than individual bores would be required at most unserviced towns.

Groundwater supply was considered for supplying the unserviced towns of Sandy Point, Waratah

Bay, Yanakie and Walkerville in SKM (2004), which concluded that such a supply would only be

financially feasible for the two smaller towns of Yanakie and Walkerville and that there was

significant uncertainty surrounding the technical feasibility without further drilling investigations.

Groundwater will continue to be a supply option for servicing small towns from local aquifers and

as a drought response measure, but is not considered a feasible alternative to cheaper surface water

options in this region of relatively low yielding aquifers.

A groundwater management area has been declared around the Tarwin area despite relatively low

groundwater usage in the area. This is because of concerns about seawater intrusion and

contamination of regional groundwater by septic tanks at Venus Bay. Appropriate strategies to

deal with potential health risks would need to be taken into account in the feasibility of supplying

towns in the vicinity of Venus Bay with groundwater.

B.3 Rainwater

Rainwater is used widely in rural Australia for domestic purposes such as drinking, food

preparation and bathing. Rainwater can provide a practical way of supplementing a town‟s water

supply as it is a low health risk alternative to reticulated water supply.

The quality of water collected in household tanks is generally understood not to be as consistently

high as that provided through a reticulated system1. This is because maintenance of the system is

the responsibility of householders, who do not necessarily undertake that maintenance regularly or

appropriately. Poor water quality has also been linked to the presence of lead flashing on some

roofs. There is also a particular risk for sub-surface tanks in which surface run-off can infiltrate

into the water supply causing contamination, but these types of tanks are generally rare in domestic

applications.

Rainwater tanks are increasingly being used for non-potable use, such as watering gardens and

toilet flushing. The Victorian Government‟s five-star home standards requires new homes to have

a rainwater tank that provides water for toilet flushing (or equivalent volumes delivered through

communal stormwater or reuse) if a solar hot water system is not included in the design2.

Rainwater is not recommended as a sole source of water as it is generally not sufficiently reliable.

On a national scale, the Bureau of Meteorology classifies annual rainfall variability in South

Gippsland as low to moderate, indicating that rainfall has historically been very reliable3. Rainfall

in South Gippsland in individual years can nevertheless vary considerable. Under dry conditions,

rainwater tanks are at risk of failure and residents are likely to require water sourced by other

means.

1 EnHealth (2004) Guidelines for the use of Rainwater Tanks

2 Watersmart (2006) Water Supply-Demand Strategy for Melbourne 2006-2055. Draft.

3 Bureau of Meteorology (2006) http://www.bom.gov.au/climate/map/variability/VARANN.GIF

http://www.bom.gov.au/climate/map/variability/VARANN.GIF

B.4 Greywater

Grey water encompasses all household wastewater excluding that derived from toilets and urinals.

The quality of greywater varies significantly depending on the source and activity within the

household but it can contain microbial pathogens, cleaning solutions and other contaminants. In

light of this, it has the potential to be hazardous to human health if not adequately treated.

Although it is possible to treat grey water to a level that is safe for human consumption it is not cost

effective to treat it to a level which is suitable for drinking, food preparation, personal washing and

spa and pool top-ups4. In addition to cost considerations, the human health consequences of

treatment failure are potentially high.

The risks associated with use of greywater for laundry trough, toilet flushing, outdoor use, fire-

fighting and surface irrigation are classed as medium. Treatment systems must consistently achieve

a high standard of treatment due to the potentially high degree of pathogens that may be present.

Greywater is a diffuse source of water, meaning that it is difficult to collect and supply at anything

other than a property scale. An example of community greywater recycling is the Bridgewater

development in Western Australia, where all greywater from 380 homes is recycled for irrigation.

This scheme is effective at a community scale because it was integrated into the design of the new

development rather than being retrofitted.

B.5 Stormwater

Stormwater in urban surface water runoff captured from rain events. The quality of stormwater

varies according to the source area. Stormwater may contain a variety of contaminants including

microbial pathogens, oils and grease, leachate from vegetation and nutrients.

Like greywater it is possible to treat stormwater to a standard suitable for domestic purposes such

as drinking and food preparation. This treatment is costly and the risk to human health of failure of

treatment is considerable5. In light of this the use of stormwater for these purposes is not

recommended.

The risk for personal washing, swimming pools and spas, laundry trough and washing machines is

classified as medium after treatment6. For multiple sites, treatment should include catchment

management, storage management, clarification (removal of solids) and disinfection.

4 Hyder Consulting (2005) Alternative Urban Water Supplies- Regulatory Review



Stormwater has been successfully harvested in the City of Salisbury in South Australia7. This

particular scheme uses an artificial wetland to capture and treat stormwater, let it infiltrate into

groundwater and then later pump that water from groundwater when it is required to meet urban

demands.

Applications for residential water use tend to be less favoured than other source substitution

options such as rainwater tanks and recycling of treated effluent. Stormwater is typically generated

in large volumes over short periods of time and therefore usually needs to be stored if it is to be

used for urban use. The cost of storage is greater than most other alternative supply options

presented in this paper. Stormwater harvesting at a scale larger than an individual property can

also require a third pipe system to deliver the stormwater. Third pipe systems (for recycling of

treated wastewater) have been installed for example in the Aurora (Victoria) and Mawson Lakes

(South Australia) residential developments8.

Harvesting stormwater can have water quality benefits to downstream waterways. Ladson et.al.

demonstrated a relationship between the amount of impervious area in a catchment with water

quality of downstream waterways9.

B.6 Local desalination of sea water

Desalination is a process which separates dissolved minerals and impurities from sea water, salty

water or treated wastewater. Desalinated water is suitable for drinking and food preparation.

The key advantage of desalination is that it uses sea water and therefore is independent of climate

variability. This means that is provides a reliable source of water and removes the pressure from

existing surface and groundwater sources.

Although the cost of the technologies used in desalination of seawater has reduced significantly it

is still a costly option. There are also environmental concerns associated with desalination. In the

first instance it is a high energy option and therefore has consequences in terms of greenhouse gas

emissions if those energy costs are not offset. In addition, the removal of fresh water means that

hyper-saline solution is discharged into the sea. This can have negative consequences for the

marine environment and can require costly diffusers extending into the sea over long distances.

Desalination package plants of 0.5 ML/d can typically be installed for several hundred thousand

dollars, with the costs of disposing of the waste brine stream being in addition to this.


8 http://www.goldcoast.qld.gov.au/t_gcw.asp?pid=5894

9 Ladson et.al. (2005) Improving Stream Health in Urban Areas by Reducing Runoff Frequency from

Impervious Surfaces. 29th

Hydrology and Water Resources Symposium, Canberra, 21-23 February 2005.

http://www.goldcoast.qld.gov.au/t_gcw.asp?pid=5894

Appendix C Nyora Planning Controls

Nyora is located within the Shire of South Gippsland. The South Gippsland Shire Council is

responsible for governing the use and development of all land within the municipality. They

exercise this governance through zoning. Each zone outlines a specific use that is allowed on the

site and the requirements of any development or works. Figure E-1 shows the zones surrounding

the township of Nyora.

As can be seen from Figure E-1, the land uses surrounding the township of Nyora are a Low

Density Residential Zone (LDRZ), a Rural Living Zone (RLZ), and a Farming Zone (FZ). These

zones allow varying levels of density of residential development thus influencing future population

growth. Table E-1 outlines the size of lots permitted and the number of dwellings allowed on each

lot.

Figure E-1: Zone Map of Nyora Township and Surrounding Land

Legend

Farming Zone

Low Density

Residential Zone

Rural Living Zone

Nyora

Table E-1: Summary of Density Controls for Relevant Zones

Density Controls

LDRZ Each lot must be at least 0.4 hectare. There must be only one dwelling on each lot.

RLZ Each lot must be at least 8 hectares. There must be only one dwelling on each lot.

FZ The lot must be at least 40 hectares. There must be only one dwelling on each lot.

Source: http://www.dse.vic.gov.au/planningschemes/southgippsland

Clause 21.02-3 of the Municipal Strategic Statement in the South Gippsland Shire Planning

Scheme states that there is “a need to plan for housing and facilities to cater for anticipated

population growth in the north-west of the Shire” (which includes Nyora). This is relevant as it

indicates a willingness to allow additional residential development in the area in the future.

Based on a desktop assessment, it appears that the area surrounding Nyora has already been

developed to the full capacity allowed by the existing planning controls. Most lots appear to

already have the one dwelling permitted. There may be capacity for a small number of new

dwellings in the LDRZ and RLZ, however this number is small enough to not significantly affect

future population growth or demand in this town. An amendment to the planning scheme would be

required to allow further significant development, which is typically a process which takes 1-2

years to complete.

Water Supply Demand Strategy - Addendum

1 October 2012

Water Supply Demand Strategy - Addendum

1 October 2012

This document was prepared with the assistance of: Sinclair Knight Merz ABN 37 001 024 095 Level 11, 452 Flinders Street, Melbourne VIC 3000 PO Box 312, Flinders Lane, Melbourne VIC 8009 Tel: +61 3 8668 3100 Fax: +61 3 8668 3400 Web: www.skmconsulting.com The SKM logo trade mark is a registered trade mark of Sinclair Knight Merz Pty Ltd. LIMITATION: This report has been prepared on behalf of and for the exclusive use of Sinclair Knight Merz Pty Ltd’s Client, and is subject to and issued in connection with the provisions of the agreement between Sinclair Knight Merz and its Client. Sinclair Knight Merz accepts no liability or responsibility whatsoever for or in respect of any use of or reliance upon this report by any third party.

PAGE i

Contents 1. Introduction 2

2. SGW’s strategy for advancing the business case for the Northern Towns 3

3. Differences between SGW’s WSDS and DSE’s guidelines 4

4. Summary of Communication Process for the WSDS 6

5. Example Annual Water Security Outlook 8

6. Alternative Water Atlas 11

7. Current Government Policies and Implications for SGW’s WSDS 21

8. References 22

1. Introduction South Gippsland Water (SGW) released its Water Supply Demand Strategy (WSDS) for public consultation in May 2011 (SGW, 2011). As part of SGW’s ongoing long-term water planning activities, the 2011 update to our WSDS commenced in late 2009 and the majority of the strategy had been completed prior to the release of the Victorian State Government’s guidelines for preparing a WSDS. The guidelines were released as a first draft in late 2010 and revised throughout 2011, with the final guidelines being released in October 2011 (DSE, 2011a).

This addendum to our WSDS provides additional information about our strategy to better align with the final guidelines, and to clarify any differences between the content of our strategy and the DSE guidelines. This addendum covers:

SGW’s strategy for advancing the business case for securing supply for SGW’s northern towns;

Clarification of areas where our WSDS deviates from the guidelines;

Documentation of community consultation undertaken to develop the WSDS;

An example water security outlook;

An Alternative Water Atlas; and

A short discussion of relevant government policies and implications for SGW’s WSDS.

2. SGW’s strategy for advancing the business case for the Northern Towns

South Gippsland Water has had meetings with DSE and the Minister for Water and Local Member and Deputy Premier Peter Ryan in relation to SGW’s Water Supply Demand Strategy and Business case to connect into the Melbourne Water Supply System. The Business Case presents the justification for investment in a connection to the Melbourne system and related water supply augmentation works for the Northern and Southern parts of SGW’s supply system which include interlinking by pipe work.

SGW is progressing the preparation of detailed business case supporting documentation that can be included with a submission in a future State budgetary process and for consideration in the development of our Water Plan.

SGW’s proposal is to proceed with the functional and detailed design works associated with the pipeline connection works, and to have this work completed to allow construction to commence on allocation of State funds.

Interim short term alternative strategies for balancing supply and demand that SGW will adopt are as follows:

Lance Creek - The Lance Creek system supplying Wonthaggi, Cape Paterson and Inverloch will be connected to the Melbourne system and will be able to source additional water from the Melbourne system as required to meet any imposed demands.

Little Bass – In the Little Bass system supplying Poowong, Loch and Nyora, we will apply restrictions and cart water to augment supply as required.

Korumburra – If required we will apply restrictions, as well as utilise and recommission the Korumburra to Leongatha saline outfall pipeline in the same manner as was done in the 2006/07 drought to transfer water from Leongatha to Korumburra.

Leongatha – If required we will apply restrictions, as well as utilise the Tarwin River and Coalition Creek pumps to transfer water into the system. We can also utilise the Leongatha bores installed during the 2006/07 drought.

3. Differences between SGW’s WSDS and DSE’s guidelines

SGW was mindful of the content of the draft DSE guidelines when finalising our WSDS. Some differences, and their implications for SGW’s long-term planning, are discussed as follows:

Climate change – The guidance on scenario modelling for climate change was not made available from DSE until mid 2011, by which time SGW had already completed its water resource modelling for the WSDS. The basis for SGW’s climate change assessments was outlined in Section 1.5 of our WSDS. We utilised the year 2060 medium climate change conditions, as estimated from CSIRO’s atmospheric modelling results presented in Jones and Durack (2005). This was consistent with the data used by DSE in its draft Gippsland Region Sustainable Water Strategy (DSE, 2010). A summary of the adjustments made by SGW to climate and streamflow (runoff) data for climate change scenarios, as well as DSE’s most recent guidance on this issue, is presented in Table 1. Changes in runoff are the main influence on SGW’s planning decisions for climate change uncertainty. The change in runoff under year 2060 medium climate change was below the figure recommended in the more recent guidance from DSE on this issue. However SGW has modelled the full range of anticipated climate change outcomes through the presentation of the return to dry conditions scenario, which forms an upper bound on likely climate change impacts. Given the inherent uncertainties in current climate change projections, SGW’s use of a mid-range and upper bound estimate of climate change impacts covers off on likely climate change impacts. Use of the more recent climate change estimates would not alter SGW’s WSDS outcomes.

Table 1 Comparison of adjustments to historical data for year 2060 climate change

Variable Adjustment used in SGW’s WSDS Adjustment recommended in DSE’s WSDS guidelines

Year 2060 change in rainfall -3% -8% (with range -4% to -15%) Year 2060 change in potential evapotranspiration

+8% +8% (with range +5% to +8%)

Year 2060 change in runoff -15% -23% (with range -9% to -40%) Return to dry conditions As per DSE guidelines. For example, -44% reduction in runoff in the

Tarwin River at Meeniyan.

Level of service objectives – In the DSE guidelines it was recommended that a minimum and agreed level of service be specified for customers. SGW’s level of service objectives were presented in Section 2.3 of the WSDS. These included experiencing any restrictions not more frequently than 1 year in 10 and experiencing more severe restrictions not more than 1 year in 15 on average over the long-term. In other words, the likelihood of not experiencing restrictions in

any given year in the long-term is 90%, with a 93% likelihood of not experiencing severe restrictions. This forms SGW’s agreed level of service, as specified more recently in our Drought Response Plan (SGW, 2012). SGW’s minimum level of service is covered in the WSDS by constraining yield estimates to be “without running out of water in the most severe drought” over the historical climate sequence. SGW has subsequently adopted DSE’s suggested terminology on this issue in our Drought Response Plan (SGW, 2012), where a minimum level of service has been specified as the volume of unrestrictable demand (i.e. in-house use plus most commercial/industrial demand) in each supply system. This update to terminology for the minimum and agreed level of service does not change any outcomes in the WSDS.

4. Summary of Communication Process for the WSDS

South Gippsland Water has undertaken an extensive Customer Consultation Process with its 2011 Water Supply Demand Strategy which included:

South Gippsland Water’s Water Supply Demand Strategy and the Business Case for our Northern and Southern Systems are located on the Corporation’s web site;

Briefings by the Managing Director to South Gippsland Water regulatory bodies and water related organisations including Local State and Federal Members, Bass Coast and South Gippsland Shire Councillors, Department of Sustainability and Environment, Vic Water Industry Groups, West Gippsland Catchment Management Authority and South Gippsland Water’s major customers, all who expressed support for the Strategy;

Advertising in the local press of South Gippsland Water’s proposed long term strategy to manage water in the South Gippsland Region and presentations to local community groups such as Lions and Rotary;

Article included in the South Gippsland Water Customer News letter; and

Community information sessions conducted in major townships.

Customer Focus Groups - Table 2 documents customer response in regard to the proposed WSDS capital works projects.

South Gippsland Water customer stakeholder consultation process has been extensive and remains open for comment. The typical feedback has been supportive of the concept.

Table 2 Outcomes from Customer Focus Groups

5. Example Annual Water Security Outlook An example Annual Water Security Outlook has been presented for the Lance Creek supply system, supplying Wonthaggi, Cape Paterson and Inverloch. This template will be used to prepare outlooks in November each year for all supply systems. Minor deviations from this template will be needed for other supply systems with different sources of supply. For example, for run-of-river systems such as Dumbalk and Meeniyan, forecast streamflow will be presented rather than forecast volume in storage. For Yarram and Leongatha, volumes of groundwater used relative to licensed volume for the year will also be presented.

6. Alternative Water Atlas A range of alternative water supplies have been investigated as part of SGW’s long-term water planning. The WSDS included consideration of stormwater (Section 3.8 of WSDS), treated wastewater (Section 3.9 of WSDS), groundwater (currently utilised at Leongatha, Korumburra and Yarram), and a range of alternative water supply options for currently unserviced coastal towns that also included rainwater tanks and small scale desalination of sea water. This information is consolidated below into SGW’s Alternative Water Atlas. This atlas will form an inventory which is maintained by SGW on an ongoing basis.

Table 3 Alternative Water Atlas for SGW’s Northern Towns (Korumburra, Leongatha/Koonwarra, Poowong/Loch/Nyora)

Resource Type Northern Towns Resource Availability Groundwater Current Resource Availability:

- SGW has licences to extract up to 386.4 ML/yr in practice from 4 bores at Leongatha at up to 2.1 ML/d in total. These licences were granted in 2010. The approvals process was lengthy due to concerns from the licensing authority about potential third party and environmental impacts. One of these bores is shared with a local landholder. Future Resource Availability: - Future development of some local groundwater is constrained by poor quality and low yielding aquifers. This applies to the unincorporated areas to the east of Nyora and around Korumburra. Yields from the Korumburra Group cretaceous age bedrock sediments in this area are poor at less than 1 L/s with salinities between 1500-3000 mg/L. - Preliminary investigations into the availability of groundwater from the Coal Creek Coal Mines at Korumburra indicated high uncertainty in estimates of available volume (25-785 ML depending on mine void assumptions), water was of unknown quality and there was a risk of land subsidence if drilling in areas around mine shafts and fault lines (SKM, 2007a). - New groundwater licences in the higher yielding Leongatha GMA (near Korumburra and Leongatha) are difficult to obtain due to potential local environmental impacts and interference with existing users. No new licences are to be issued from the Koo Wee Rup WSPA (to the west of Nyora) under the Groundwater Management Plan covering this area (SRW, 2010a). In both managed areas, purchase of licences from existing users is likely to be required to access further groundwater resources. Current Use: - Leongatha bores are currently used to supply Leongatha/Koonwarra and Korumburra during drought. Potential Future Use: - The bores could also supply Poowong/Loch/Nyora if that system is connected to the Korumburra system in the next Water Plan period as planned.

Resource Type Northern Towns Resource Availability Treated Wastewater

Current Resource Availability: - In 2009/10, 638 ML of Class B treated effluent was produced at Korumburra and 547 ML of Class B treated effluent was produced at Leongatha. Class B treated effluent is suitable for most agricultural and industrial applications, but is not suitable for drinking. There is currently no wastewater treatment plant at Poowong/Loch/Nyora. A further volume of 1088 ML/yr is saline trade waste discharge from the Murray-Goulburn milk factory at Leongatha, with Burra Foods trade waste being partially treated on site before being discharged to the Korumburra Wastewater Treatment Plant. Future Resource Availability: - A wastewater treatment plant and reticulated sewerage system is currently being designed to service Poowong, Loch and Nyora. The scheme is expected to be completed in 2016/17 - The volume of treated effluent at all northern towns is expected to grow in line with increases in population in these towns. Population is expected to grow by around 50% over the next 50 years, with most of this growth occurring at Poowong/Loch/Nyora. Current Use: - Approximately 5 ML/yr of treated effluent is currently used from the standpipe at Korumburra, with the remainder supporting environmental flows in the Powlett River. - Approximately 1 ML/yr of treated effluent is currently used from the standpipe at Leongatha, with the remainder supporting environmental flows in Little Ruby Creek. Potential Future Use: - The intended reuse of treated effluent from Poowong, Loch and Nyora is for agricultural purposes. - Potential future reuse of Leongatha treated effluent at golf club.

Stormwater The volume of stormwater currently available in SGW’s northern towns has not been quantified. SGW has not pursued any stormwater proposals at the current time due to its poor water quality and low reliability. Harvesting stormwater may also result in reductions in environmental flows in the Bass River and Tarwin River catchments.

Desalination SGW does not currently have access to any desalinated water supplies. SGW’s WSDS proposes the connection of SGW’s northern towns to the Lance Creek supply system, which would provide access for the northern towns to the Victorian Desalination Plant at Wonthaggi. SGW already has bulk entitlements in place to supply up to 1,000 ML/yr from the desalination plant to Korumburra (including Poowong/Loch/Nyora) and up to 3,000 ML/yr to Leongatha. The Victorian Desalination Plant is expected to be operational in 2013. This supply option for the northern towns is the subject of a separate business case prepared by SGW.

Table 4 Alternative Water Atlas for SGW’s Southern Towns (Wonthaggi, Cape Paterson, Inverloch)

Resource Type Southern Towns Resource Availability Groundwater Current Resource Availability:

- SGW does not have any current groundwater licences in the vicinity of its southern towns. Future Resource Availability: - The area surrounding Lance Creek Reservoir, Wonthaggi, Cape Paterson and Inverloch is within an unincorporated area, which means that new groundwater licences can be issued in this area. A number of bores have been drilled in the region with groundwater salinities ranging from 1000-3000 mg/L. Eleven bores were drilled by the Department of Minerals and Energy approximately 16-18 km north east of Inverloch in 1984, where yield was suitable, but quality highly variable. Further investigation would be required to find suitable sites for groundwater extraction, which could take several months. A desktop review was undertaken in SKM (2007b) of groundwater supply potential at Inverloch. The town was supplied from groundwater between around 1945 to 1950 from a disused bore located between Surf Parade and the foreshore, close to Wave Street. SKM (2007b) indicated that potential for groundwater supply from the Strzelecki Formation was low due to poor yields. The prospect of supply from the Tertiary and Quaternary aged sediments overlying the Strzelecki Group are likely to represent a better prospect for town water supply. Information on yield and quality from these sediments is limited, and the aquifers are relatively thin, which means that they could be depleted quickly, with an additional risk of sea water intrusion. Current Use: - None. Potential Future Use: - None currently planned due to poor groundwater yields and existing access to reliable surface water supplies.

Resource Type Southern Towns Resource Availability Treated Wastewater

Current Resource Availability: - In 2009/10, 85 ML of Class C treated effluent was produced at Cape Paterson, 370 ML of Class C treated effluent was produced at Inverloch and 567 ML of Class C treated effluent was produced at Wonthaggi. Class C treated effluent is only suitable for a small range of agricultural and industrial applications such as livestock grazing and golf courses. Future Resource Availability: - No changes to the quality of treated effluent are proposed. The volume of treated effluent is expected to grow in line with increases in population in SGW’s southern towns. Population in these towns is expected to at least double over the next 50 years. Current Use: - Approximately 20-30 ML/yr of treated effluent is currently used for pasture and crop irrigation during summer at Inverloch, with the remainder discharged to the ocean at the Baxters Beach outfall. - All treated effluent at Wonthaggi and Cape Paterson is discharged to the ocean. Potential Future Use: - There is no short term reuse plan for treated effluent at Cape Paterson due to the high cost to provide a storage facility and pipeline infrastructure. - To reuse treated effluent generated in winter at Inverloch would require a winter balancing storage. There is currently no demand for additional reuse in summer. - Options for long-term reuse of treated effluent at Wonthaggi are currently being explored by SGW.

Stormwater - The volume of stormwater currently generated across the Wonthaggi urban area has been coarsely estimated at 2.8 GL/yr, but only a very small proportion of this is harvestable from rooves (SKM, 2006). The volume of stormwater currently available in SGW’s other southern towns has not been quantified. - Harvesting of stormwater water from the Wonthaggi Coal Mines was investigated in SKM (2006). This scheme involved the possibility of diverting 2.8-5.5 GL/yr of stormwater into the mines, primarily to offset many of the potential issues associated with groundwater extraction alone from the mines, such as subsidence and impacts on nearby groundwater dependent ecosystems. The stormwater stored in the mines would subsequently be extracted using groundwater bores. The option was however later dismissed as infeasible due to testing that indicated poor water quality in the mines.

Resource Type Southern Towns Resource Availability Desalination SGW does not currently have access to any desalinated water supplies. A physical

connection of 10 ML/d capacity currently exists between the Lance Creek supply system and the Victorian Desalination Plant at Wonthaggi, but the plant is not expected to be operational until 2013. SGW already has bulk entitlements in place to supply up to 1,000 ML/yr from the desalination plant to Wonthaggi, Cape Paterson and Inverloch. Draft operating rules for accessing the plant during drought have been prepared as part of SGW’s Drought Response Plan (SGW, 2012).

Table 5 Alternative Water Atlas for SGW’s Central Towns (Dumbalk, Meeniyan, Foster, Fish Creek, Toora, Port Welshpool, Welshpool and Port Franklin)

Resource Type Central Towns Resource Availability Groundwater Current Resource Availability:

- SGW does not have any licensed groundwater bores at its central towns. Future Resource Availability: - The area to the east of Toora is situated within the Yarram Water Supply Protection Area. No new licences are to be issued from this WSPA under the Groundwater Management Plan covering this area (SRW, 2010b). Purchase of licences from existing users is likely to be required to access groundwater resources. - All other central towns, including areas to the west of Toora, are situated in unincorporated areas where no cap on groundwater licences has been set. A bore pump test was undertaken on bore number 61664 at Dumbalk in 1998 (SKM, 1998). The conclusions from the test were that it was capable of yielding around 1.5 l/s (0.13 ML/d). SKM (1998) also stated that a new bore could be capable of producing 3-6 l/s. The availability of groundwater at other towns has not been assessed. Current Use: - Groundwater is not used at SGW’s other central towns. Potential Future Use: - No groundwater supply is proposed at SGW’s central towns, other than as a possible drought response measure.

Resource Type Central Towns Resource Availability Treated Wastewater

Current Resource Availability: - In 2009/10, 125 ML of Class C treated effluent was produced at Foster, 52 ML of Class C treated effluent was produced at Toora and 41 ML of Class B treated effluent was produced at Welshpool. Class B treated effluent is suitable for most agricultural and industrial applications, but is not suitable for drinking. Class C treated effluent is only suitable for a small range of agricultural and industrial applications such as livestock grazing and golf courses. Future Resource Availability: - No changes to the quality of treated effluent are proposed. The volume of treated effluent is expected to grow in line with increases in population in SGW’s central towns. Population is expected to increase across the central towns by around 8% over the next 50 years. Current Use: - Approximately 2-3 ML/yr of treated effluent is currently used in summer at Toora by the Toora Football Club, with the remainder discharged to the ocean at Toora. Foster and Toora currently discharge to Corner Inlet. Welshpool discharges to pasture irrigation. Potential Future Use: - At Foster, additional treatment is proposed. The treated effluent would be used for pasture irrigation. This would result in the closure of the ocean outfall. - At Welshpool a scheme is underway for pasture irrigation.

Stormwater The volume of stormwater currently available in SGW’s central towns has not been quantified. SGW has not pursued any stormwater proposals at the current time due to its poor water quality and low reliability. Harvesting stormwater may also result in reductions in environmental flows in the Tarwin River (Fish Creek), Franklin River (Deep Creek) and Agnes River catchments.

Desalination SGW does not currently have access to any desalinated water supplies. The possibility of connecting the central towns of Toora, Foster and Fish Creek to the Lance Creek system would provide access to the Victorian Desalination Plant at Wonthaggi, however this option has been dismissed at the current time due to high costs relative to other supply enhancement options. The possibility of connecting Dumbalk and Meeniyan to the Leongatha supply system to minimise water treatment costs is currently being investigated, and could result in these two towns having access to the Victorian Desalination Plant via Leongatha. The cost of local, small scale desalination plants supplying water from the coast to the central towns is currently more expensive than other supply options and could result in marine environmental impacts on Corner Inlet.

Table 6 Alternative Water Atlas for SGW’s Eastern Towns (Yarram, Alberton, Port Albert, Devon North)

Resource Type Eastern Towns Resource Availability Groundwater Current Resource Availability:

- SGW has licences to extract up to 60 ML/yr from the Yarram Golf Club bore at a rate up to 1 ML/d. Access to the bore is shared with the golf club under a water sharing agreement. SGW has a separate, solely owned groundwater bore from which it can extract at up to 4 ML/d. SGW is undertaking a water licence transfer program to increase its legal entitlement to water from this bore to up to 400 ML/yr. As of December 2011, 64 ML of licences had been purchased and transferred from other existing licence holders. Future Resource Availability: - Yarram is situated within the Yarram Water Supply Protection Area. No new licences are to be issued from this WSPA under the Groundwater Management Plan covering this area (SRW, 2010b). Purchase of licences from existing users is likely to be required to access further groundwater resources. Groundwater supply potential for Yarram was most recently investigated in SKM (2009). That study looked at three potential sites around Yarram and concluded that bore yields of 1-4 ML/d were achievable at all three sites. Water quality was suitable at between 150-408 mg/L TDS observed in the Latrobe Group Aquifer and 120-175 mg/L TDS in the Balook Aquifer. The report also commented on the potential to affect other groundwater users, as well as the bore depth requirements if the bore is to cater for the long-term groundwater level decline currently occurring in the region. Current Use: - 7 ML of groundwater was used by SGW in 2009/10, with 11 ML used in 2008/09. Potential Future Use: - Additional groundwater supply at Yarram is proposed in SGW’s WSDS, with a program to pursue the transfer of up to 400 ML/yr from existing licence holders.

Resource Type Eastern Towns Resource Availability Treated Wastewater

Current Resource Availability: - In 2009/10, 101 ML of Class C treated effluent was produced at Tarraville (servicing Yarram and Port Albert). Class C treated effluent is only suitable for a small range of agricultural and industrial applications such as livestock grazing and golf courses. Future Resource Availability: - No changes to the quality of treated effluent are proposed. The volume of treated effluent is expected to change in line with changes in population in SGW’s central towns. Population is expected to decrease across the eastern towns by around 11% over the next 50 years. Current Use: - All of the available treated effluent at Tarraville was used for pasture irrigation in 2009/10. Potential Future Use: - The current practice of pasture irrigation is expected to continue.

Stormwater The volume of stormwater currently available in SGW’s eastern towns has not been quantified. SGW has not pursued any stormwater proposals at the current time due to its poor water quality and low reliability. Harvesting stormwater may also result in reductions in environmental flows in the Tarra River.

Desalination SGW does not currently have access to any desalinated water supplies. The cost of local, small scale desalination plants in coastal towns is currently more expensive than other supply options and could result in marine environmental impacts.

Table 7 Alternative Water Atlas for SGW’s unserviced towns east of Wonthaggi (Sandy Point, Waratah Bay, Yanakie and Walkerville)

Resource Type Unserviced Towns Resource Availability Groundwater Groundwater supply was considered for supplying the unserviced towns of Sandy Point,

Waratah Bay, Yanakie and Walkerville in SKM (2004), which concluded that such a supply would only be financially feasible for the two smaller towns of Yanakie and Walkerville and that there was significant uncertainty surrounding the technical feasibility without further drilling investigations.

Treated Wastewater

- In 2009/10, 2 ML of Class C treated effluent was produced at Waratah Bay. All of this effluent is currently being reused on land.

Stormwater The volume of stormwater currently available in the unserviced towns of Sandy Point, Waratah Bay, Yanakie and Walkerville has not been quantified. Rainwater tanks are expected to exist on existing dwellings as the current source of drinking water. SGW has not pursued any stormwater proposals at the current time due to its poor water quality and low reliability.

Desalination SGW does not currently have access to any desalinated water supplies. SGW will keep a watching brief on the available technology and cost of local, small scale desalination plants for potential use in these currently unserviced coastal towns.

7. Current Government Policies and Implications for SGW’s WSDS

South Gippsland Water’s (SGW’s) WSDS includes information on State Government policy and regulations (see Section 3 of our WSDS). This covered SGW’s current legal entitlements to water, as well as government policy regarding future access to groundwater (within and outside of defined Water Supply Protection Areas and Groundwater Management Areas), surface water (under Sustainable Diversion Limits) and other water supplies, such as SGW’s entitlement for access to the Victorian Desalination Plant.

Since preparing the WSDS, the key policy document from the State Government relevant to SGW’s water planning is the final Gippsland Region Sustainable Water Strategy (SWS) (DSE, 2011b). SGW note the following items from the final SWS:

SGW intends to participate as a stakeholder in the development of Local Management Plans where they affect SGW’s activities;

SGW notes the currently unallocated volumes of water in the Leongatha and Tarwin GMA, however based on the assessment for our recently granted licences, accessing this unallocated water is considered difficult due to potential third party and local environmental impacts. As mentioned in the SWS, we have commenced a water trading strategy in the fully allocated Yarram WSPA;

SGW notes the caps specified in the SWS, which include 2500 ML of unallocated water across the Tarwin River catchment, 500 ML across the Powlett River catchment, 300 ML across each of the Franklin River, Albert River, Ten Mile Creek, Dividing Creek and Nine Mile Creek/Shady Crek catchments, 500 ML across other catchments where water is still available under the Sustainable Diversion Limit, and no further allocations available in the Tarra River catchment. SGW’s WSDS remains in line with these caps. When preparing the WSDS, we have considered availability of surface water in these catchments with unallocated water. This included considering accessing more water from the Tarwin River catchment, where the SWS indicates large volumes of water are available for further allocation; and

In line with Action 5.3 of the SWS, SGW has consulted with the community and stakeholders on the draft WSDS (as discussed in Section 4 of this addendum). This addendum forms our update to the WSDS.

8. References DSE (2010) Draft Gippsland Region Sustainable Water Strategy for Community Comment. August 2010.

DSE (2011a) Guidelines for the Development of a Water Supply Demand Strategy. Version 2. 10 October 2011.

DSE (2011b) Gippsland Region Sustainable Water Strategy. November 2011.

Jones, R.N. and Durack, P.J. (2005) Estimating the Impacts of Climate Change on Victoria’s Runoff using a Hydrological Sensitivity Model, CSIRO Marine and Atmospheric Research, Melbourne, 46 pp.

SGW (2011) Water Supply Demand Strategy. 7 December 2011.

SGW (2012) Drought Response Plan. 17 February 2012.

SKM (1998) Bore Pumping Test – Dumbalk. Letter from Gordon Walker of SKM to Dao Norath of SGW, dated 28 May 1998.

SKM (2004) Long-term Water Planning Strategy. Final. 8/07/2004

SKM (2006) Wonthaggi Coal Mine Water Use. Stage 2 Report – Preliminary Investigation into the Feasibility of Using Coal Mine Water for Potable Supply and Recharge with Urban Stormwater. Final. 31 August 2006.

SKM (2007a) Potential Groundwater Supplies around Korumburra. Final. 21 February 2007. Prepared for South Gippsland Water.

SKM (2007b) Groundwater Resource Potential in Inverloch, South Gippsland. Letter from Andrew Harrison of SKM to Graeme Watkins of South Gippsland Water, 4/4/2007.

SKM (2009) Yarram Groundwater Investigation. Augmentation of the Yarram Water Supply System. Prepared for South Gippsland Water.

SRW (2010a) Groundwater Management Plan. Koo Wee Rup Water Supply Protection Area. Prepared by Southern Rural Water.

SRW (2010b) Groundwater Management Plan. Yarram Water Supply Protection Area. Prepared by Southern Rural Water.

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